diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Button.cpp b/SequenceAlignmentVis/SequenceAlignmentVis/Button.cpp
index a3bf855..41d76e8 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Button.cpp
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Button.cpp
@@ -3,7 +3,7 @@
 using namespace glm;
 using namespace std;
 
-Button::Button(vec3 color, float x, float y, float width, float height, string str, Mesh* mesh, Shader& shader, Shader& textShader, Engine& engine,function<void(Engine& engine)> action):DrawableObject(shader,color),textShader(textShader),engine(engine),mesh(mesh),text(nullptr),action(action) {
+Button::Button(vec3 color, float x, float y, float width, float height, string str, Mesh* mesh, Engine& engine,function<void(Engine& engine)> action):DrawableObject(engine.getShader(),color),textShader(engine.getTextShader()),engine(engine),mesh(mesh),text(nullptr),action(action) {
 	setupText(str, x, y, width, height);
 	setLocation(vec3(x, y, 6.1));
 	setScale(vec3(width, height, 1));
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Button.h b/SequenceAlignmentVis/SequenceAlignmentVis/Button.h
index 851947e..038789e 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Button.h
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Button.h
@@ -8,7 +8,7 @@
 
 class Button :public DrawableObject {
 public:
-	Button(glm::vec3 color, float x,float y, float width, float height,std::string str,Mesh* mesh, Shader& shader,Shader& textShader, Engine& engine,std::function<void(Engine& engine)> action);
+	Button(glm::vec3 color, float x,float y, float width, float height,std::string str,Mesh* mesh,Engine& engine,std::function<void(Engine& engine)> action);
 	Button(const Button& other);
 	virtual ~Button();
 	void onClick();
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Engine.cpp b/SequenceAlignmentVis/SequenceAlignmentVis/Engine.cpp
index 8120e11..a30febc 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Engine.cpp
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Engine.cpp
@@ -1,6 +1,8 @@
 #include <Windows.h>
 #include "Engine.h"
 #include "UserInterface.h"
+#include "MessageBox.h"
+
 using namespace glm;
 using namespace std;
 
@@ -38,11 +40,17 @@ void Engine::run() {
 			glReadPixels(mouse.xPos, mouse.yPos, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, data);
 			int ind = getId(vec3(data[0], data[1], data[2]));
 			DrawableObject* selObj = currScene->getSelectedObj();
-			if (selObj != nullptr) { selObj->onRelease(); }
 			if (ind >= 0) {
+				if (selObj != nullptr && selObj->getId()!=ind) { 
+					printf("ind:%d\nselObj:%d\n", ind, selObj->getId());
+					selObj->onRelease(); 
+				}
 				currScene->getObject(ind).onClick();
 			}
 			else {
+				if (selObj != nullptr) {
+					selObj->onRelease();
+				}
 				currScene->onClickBackground();
 			}
 		}
@@ -55,6 +63,15 @@ void Engine::run() {
 	}
 }
 
+void Engine::showAlert(string title, string text) {
+	if (currScene == nullptr) { return; }
+	UI::Messagebox m(vec3(0.8f, 0.2f, 0.2f), vec3(0.0f, 0.0f, 0.0f), 6.0f, 8.0f, 1.0f, 1.0f, title, text, *this);
+	m.setOnDismiss([](Engine& e) {e.cont(); });
+	int ind = currScene->addObject(&m);
+	currScene->setSelectedObj(&(currScene->getObject(ind)));
+	halt();
+}
+
 void Engine::clearScene() {
 	if (currScene != nullptr) {
 		delete(currScene);
@@ -81,6 +98,7 @@ void Engine::clearAdditionalFunctions() {
 }
 
 void Engine::callAdditionalFunctions() {
+	if (!runAdditionalFunctions) { return; }
 	for (unsigned int i = 0; i < additionalFunctions.size(); ++i) {
 		bool del = !additionalFunctions[i]();
 		if (del) {
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Engine.h b/SequenceAlignmentVis/SequenceAlignmentVis/Engine.h
index 56da025..50a5a77 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Engine.h
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Engine.h
@@ -14,7 +14,10 @@ class Engine {
 	virtual ~Engine();
 	void run();
 	void changeScene(Scene* newScene);
+	void showAlert(std::string title, std::string text);
 
+	inline void halt() { runAdditionalFunctions = false; }
+	inline void cont() { runAdditionalFunctions = true; }
 	inline void addAdditionalFunction(std::function<bool()> func) { additionalFunctions.push_back(func); }
 	inline Display& getDisplay() { return d; }
 	inline Shader& getShader() { return *shader; }
@@ -25,6 +28,7 @@ class Engine {
 	mutable std::mutex mtx;
 	std::thread::id drawingThread;
 	std::vector<std::function<bool()>> additionalFunctions;
+	bool runAdditionalFunctions = true;
 	bool isRunning = false;
 	Scene* currScene;
 	Shader* shader;
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/MessageBox.cpp b/SequenceAlignmentVis/SequenceAlignmentVis/MessageBox.cpp
new file mode 100644
index 0000000..707f212
--- /dev/null
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/MessageBox.cpp
@@ -0,0 +1,135 @@
+#include "Messagebox.h"
+#include "Engine.h"
+#include <iostream>
+
+const float Z_COORDINATE = 4.0f;
+const float TITLE_SIZE_FACTOR = 1.6f;
+const float TEXT_SIZE_FACTOR = 0.8f;
+const int LETTERS_PER_LINE = 10;
+const float Z_OFFSET = -0.1f;
+
+using namespace glm;
+using namespace std;
+
+namespace UI {
+	Messagebox::Messagebox(vec3 color, vec3 textColor, float width, float height, float x, float y, string title, string text, Engine& e) : DrawableObject(e.getShader(), color), textShader(e.getTextShader()), textColor(textColor), width(width), height(height), x(x), y(y),e(e){
+		setupText(title, text);
+		createMesh();
+	}
+
+	Messagebox::Messagebox(const Messagebox& other) : DrawableObject(other), textShader(other.textShader), textColor(other.textColor), width(other.width), height(other.height), x(other.x), y(other.y),onDismiss(other.onDismiss),e(other.e){
+		copyText(other);
+		createMesh();
+	}
+
+	Messagebox::~Messagebox() {
+		clear();
+	}
+
+	void Messagebox::draw(Shader* shader, mat4 VP) {
+		if (titleInd == -1) {
+			titleInd = scn->addObject(title);
+		}
+		for (unsigned int i = 0; i < text.size(); ++i) {
+			if (textInd[i] == -1) {
+				textInd[i] = scn->addObject(text[i]);
+			}
+		}
+		Shader& s = shader != nullptr ? *shader : defaultShader;
+		glm::mat4 MVP = VP*modelMatrix;
+		glm::vec3 id = getIdVec();
+		s.Bind();
+		s.Update(MVP, modelMatrix);
+		s.setColor(color, id);
+		if (mesh != nullptr) {
+			mesh->Draw();
+		}
+
+	}
+
+	DrawableObject* Messagebox::clone() {
+		return new Messagebox(*this);
+	}
+
+	void Messagebox::onClick() {
+		scn->setSelectedObj(this);
+	}
+
+	void Messagebox::onRelease() {
+		onDismiss(e);
+		scn->removeDrawable(getId());
+	}
+
+	void Messagebox::onKeyClick(int key) {
+
+	}
+
+	void Messagebox::setupText(string title, string text) {
+		float titleSize = TITLE_SIZE_FACTOR*(width / title.size());
+		float textSize = 2*(width / LETTERS_PER_LINE);
+		vec3 titleLocation(x+width/2-titleSize, y + height / 2- titleSize /2, Z_COORDINATE);
+		this->title = new Text(titleLocation, textColor, titleSize, title, textShader);
+		this->title->setZOffset(Z_OFFSET);
+		titleInd = -1;
+		float currY = y + height / 2 - 2 * titleSize;
+		while (text.size() > 0) {
+			string prefix = text.substr(0, LETTERS_PER_LINE);
+			vec3 textLocation(x + width / 2 - textSize, currY, Z_COORDINATE);
+			this->text.push_back(new Text(textLocation, textColor, textSize, prefix, textShader));
+			this->text[this->text.size() - 1]->setZOffset(Z_OFFSET);
+			this->textInd.push_back(-1);
+			if (LETTERS_PER_LINE >= text.size()) {
+				text = "";
+			}else {
+				text = text.substr(LETTERS_PER_LINE, text.size());
+			}
+			currY = currY - textSize;
+		}
+	}
+
+	void Messagebox::createMesh() {
+		Vertex vertices[] =
+		{
+			Vertex(glm::vec3(x + width / 2.0f, y - height / 2, Z_COORDINATE), vec2(0,0), glm::vec3(0, 0, -1),color),
+			Vertex(glm::vec3(x - width / 2.0f, y - height / 2, Z_COORDINATE), vec2(1,0), glm::vec3(0, 0, -1),color),
+			Vertex(glm::vec3(x - width / 2.0f, y + height / 2, Z_COORDINATE), vec2(1,1), glm::vec3(0, 0, -1),color),
+			Vertex(glm::vec3(x + width / 2.0f, y + height / 2, Z_COORDINATE), vec2(0,1), glm::vec3(0, 0, -1),color),
+		};
+
+		unsigned int indices[] = { 3, 0, 1,
+			3, 1, 2
+		};
+		mesh = new Mesh(vertices, sizeof(vertices) / sizeof(vertices[0]), indices, sizeof(indices) / sizeof(indices[0]));
+	}
+
+	void Messagebox::copyText(const Messagebox& other) {
+		this->title = static_cast<Text*>(other.title->clone());
+		titleInd = -1;
+		for (auto it = other.text.begin(); it != other.text.end(); ++it) {
+			text.push_back(static_cast<Text*>((*it)->clone()));
+			textInd.push_back(-1);
+		}
+	}
+
+	void Messagebox::clear() {
+		if (mesh != nullptr) {
+			delete(mesh);
+			mesh = nullptr;
+		}
+		if (title != nullptr) {
+			delete(title);
+			if (titleInd != -1) {
+				scn->removeDrawable(titleInd);
+			}
+		}
+		for (unsigned int i = 0; i < text.size(); ++i) {
+			Text* curr = text[i];
+			if (curr != nullptr) {
+				delete(curr);
+				if (textInd[i] != -1) {
+					scn->removeDrawable(textInd[i]);
+				}
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/MessageBox.h b/SequenceAlignmentVis/SequenceAlignmentVis/MessageBox.h
new file mode 100644
index 0000000..00e6d61
--- /dev/null
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/MessageBox.h
@@ -0,0 +1,42 @@
+#ifndef MESSAGE_BOX_H_
+#define MESSAGE_BOX_H_
+
+#include "Object.h"
+#include <functional>
+
+class Text;
+class Engine;
+
+namespace UI {
+	class Messagebox :public DrawableObject {
+	public:
+		Messagebox(glm::vec3 color, glm::vec3 textColor, float width, float height, float x, float y, std::string title, std::string text, Engine& e);
+		Messagebox(const Messagebox& other);
+		virtual ~Messagebox();
+
+		void draw(Shader* shader, glm::mat4 vp);
+		DrawableObject* clone();
+		void onClick();
+		void onRelease();
+		void onKeyClick(int key);
+		
+		void setOnDismiss(std::function<void(Engine&)> callback) { onDismiss = callback; }
+	private:
+		void setupText(std::string title, std::string text);
+		void createMesh();
+		void copyText(const Messagebox& other);
+		void clear();
+		float width, height, x, y;
+		glm::vec3 textColor;
+		Engine& e;
+		Shader& textShader;
+		Mesh* mesh;
+		Text* title;
+		int titleInd;
+		std::vector<Text*> text;
+		std::vector<int> textInd;
+		std::function<void(Engine&)> onDismiss = [](Engine&e) {};
+	};
+}
+
+#endif
\ No newline at end of file
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Object.cpp b/SequenceAlignmentVis/SequenceAlignmentVis/Object.cpp
index bb9ea88..519b507 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Object.cpp
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Object.cpp
@@ -1,11 +1,12 @@
 #include "Object.h"
 #include "Scene.h"
+
 DrawableObject::DrawableObject(Shader& defaultShader, glm::vec3 color) :id(-1), defaultShader(defaultShader), color(color){
 
 }
 
 glm::vec3 DrawableObject::getIdVec() {
-	int tempId = getId();
+	int tempId = getId()+1;
 	int ri = tempId % 256;
 	tempId = tempId / 256;
 	int gi = tempId % 256;
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Object.h b/SequenceAlignmentVis/SequenceAlignmentVis/Object.h
index ea9f638..419082b 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Object.h
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Object.h
@@ -16,12 +16,16 @@ class DrawableObject {
 	DrawableObject(Shader& defaultShader, glm::vec3 color);
 	DrawableObject(const DrawableObject& other) :defaultShader(other.defaultShader), color(other.color), location(other.location), rotate(other.rotate),scale(other.scale), modelMatrix(other.modelMatrix) {	}
 	
+	virtual ~DrawableObject(){}
+
 	virtual void draw(Shader* shader, glm::mat4 vp) = 0;
 	virtual DrawableObject* clone() = 0;
 	virtual void onClick() = 0;
 	virtual void onRelease() = 0;
 	virtual void onKeyClick(int key) = 0;
 
+	
+
 	inline void setId(int id) { this->id = id; }
 	inline void setLocation(glm::vec3 location) { this->location = location; updateModelMatrix(); }
 	inline void setRotate(glm::vec3 axis, float deg) { this->rotate = glm::rotate(rotate, deg, axis); updateModelMatrix();  }
@@ -50,7 +54,7 @@ class Object3D:public DrawableObject {
 public:
 	Object3D(glm::vec3 color,Mesh* mesh,Shader& shader);
 	Object3D(const Object3D& other);
-	~Object3D();
+	virtual ~Object3D();
 
 	inline void setTexture(Texture* tex) { this->tex = tex; }
 	inline void resetTexture() { this->tex = nullptr; }
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/RadioButton.h b/SequenceAlignmentVis/SequenceAlignmentVis/RadioButton.h
index 634641b..3da1e20 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/RadioButton.h
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/RadioButton.h
@@ -17,7 +17,7 @@ class RadioButton :public DrawableObject {
 public:
 	RadioButton(float x, float y, std::string str, Shader& shader, T value);
 	RadioButton(const RadioButton& other);
-	~RadioButton();
+	virtual ~RadioButton();
 	void draw(Shader* shader, glm::mat4 vp);
 	DrawableObject* clone();
 	void onClick();
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Scene.cpp b/SequenceAlignmentVis/SequenceAlignmentVis/Scene.cpp
index 72892ea..3e2050a 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Scene.cpp
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Scene.cpp
@@ -133,8 +133,6 @@ void Scene::onClickBackground() {
 }
 
 int Scene::addObject(DrawableObject* object) {
-	bool shouldLock = lockingThread != std::this_thread::get_id();
-	if (shouldLock) { mtx.lock(); }
 	DrawableObject* objectToAdd = object->clone();
 	objectToAdd->setScene(this);
 	bool text = &object->getDefaultShader() == textShader;
@@ -149,9 +147,8 @@ int Scene::addObject(DrawableObject* object) {
 	else {
 		list.push_back(objectToAdd);
 	}
-	objectToAdd->setId(!text ? (ind+1) : -1);
+	objectToAdd->setId(!text ? (ind) : -1);
 	int ans = text ? -1 - ind : ind;
-	if (shouldLock) { mtx.unlock(); }
 	return ans;
 }
 
@@ -167,18 +164,16 @@ void Scene::clearFontTexture() {
 }
 
 void Scene::removeDrawable(int ind) {
-	bool shouldLock = lockingThread != std::this_thread::get_id();
-	if (shouldLock) { mtx.lock(); }
 	vector<DrawableObject*>& list = ind >= 0 ? objects : textObjects;
 	int corrInd = ind >= 0 ? ind : -ind - 1;
 	vector<int>& freeIndices = ind >= 0 ? freeIndicesObjects : freeIndicesTextObjects;
 	if (corrInd >= (int)list.size()) { return; }
 	if (list[corrInd] != nullptr) {
+		printf("deleting\n");
 		delete(list[corrInd]);
 		list[corrInd] = nullptr;
 		freeIndices.push_back(corrInd);
 	}
-	if (shouldLock) { mtx.unlock(); }
 }
 
 DrawableObject& Scene::getObject(int ind) {
@@ -346,6 +341,6 @@ void Menu::addButton(float x, float y, float width, float height, string text, f
 }
 
 void Menu::addButton(vec3 color,float x, float y, float width, float height, string text, function<void(Engine& engine)> action) {
-	Button button(color, x, y, width, height, text,cubeMesh,engine.getShader(), engine.getTextShader(), engine, action);
+	Button button(color, x, y, width, height, text,cubeMesh,engine, action);
 	addObject(&button);
 }
\ No newline at end of file
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj b/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj
index 2c25372..6150ce1 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj
@@ -122,6 +122,7 @@
     <ClInclude Include="Aligner.h" />
     <ClInclude Include="Button.h" />
     <ClInclude Include="Engine.h" />
+    <ClInclude Include="MessageBox.h" />
     <ClInclude Include="Object.h" />
     <ClInclude Include="Display.h" />
     <ClInclude Include="DPTable.h" />
@@ -143,6 +144,7 @@
     <ClCompile Include="Aligner.cpp" />
     <ClCompile Include="Button.cpp" />
     <ClCompile Include="Engine.cpp" />
+    <ClCompile Include="MessageBox.cpp" />
     <ClCompile Include="Object.cpp" />
     <ClCompile Include="Display.cpp" />
     <ClCompile Include="DPTable.cpp" />
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj.filters b/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj.filters
index 60819cd..c376edc 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj.filters
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/SequenceAlignmentVis.vcxproj.filters
@@ -90,6 +90,9 @@
     <ClInclude Include="RadioButton.h">
       <Filter>Header Files\UI</Filter>
     </ClInclude>
+    <ClInclude Include="MessageBox.h">
+      <Filter>Header Files\UI</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="mainTester.cpp">
@@ -149,5 +152,8 @@
     <ClCompile Include="RadioButton.cpp">
       <Filter>Source Files\UI</Filter>
     </ClCompile>
+    <ClCompile Include="MessageBox.cpp">
+      <Filter>Source Files\UI</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Textbox.cpp b/SequenceAlignmentVis/SequenceAlignmentVis/Textbox.cpp
index 87e7209..b1e2392 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Textbox.cpp
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Textbox.cpp
@@ -91,7 +91,6 @@ void TextBox::createMesh() {
 		3, 1, 2
 	};
 	mesh = new Mesh(vertices, sizeof(vertices) / sizeof(vertices[0]), indices, sizeof(indices) / sizeof(indices[0]));
-
 }
 
 void TextBox::clearText() {
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.cpp b/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.cpp
index 38e228c..121522d 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.cpp
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.cpp
@@ -20,6 +20,7 @@ const vec3 GREEN_COLOR = vec3(0.2f, 0.8f, 0.2f);
 const vec3 BLUE_COLOR = vec3(0.1f, 0.1f, 1.0f);
 const vec3 BLACK_COLOR = vec3(0.0f, 0.0f, 0.0f);
 const vec3 GRAY_COLOR = vec3(0.8, 0.8, 0.9);
+const vec3 RED_COLOR = vec3(1.0f, 0.0f, 0.0f);
 
 const float INIT_X = 5.0f;
 const float INIT_Y = 5.0f;
@@ -125,8 +126,13 @@ bool Visualizer::createScene() {
 	auto func = [this](Engine& e) {
 		stop = !stop;
 	};
-	Button b(GREEN_COLOR, 8.0f, 8.0f, 2.0f, 1.0f, "Stop", scene->getCubeMesh(), engine.getShader(), engine.getTextShader(), engine, func);
+	Button b(GREEN_COLOR, 2.0f, 8.0f, 2.0f, 1.0f, "Stop", scene->getCubeMesh(),engine, func);
+	Button exit(RED_COLOR, 8.0f, 8.0f, 2.0f, 1.0f, "Exit", scene->getCubeMesh(), engine, [this](Engine& e) {
+		e.changeScene(prevScene);
+		delete(this);
+	});
 	scene->addObject(&b);
+	scene->addObject(&exit);
 	if (alignerptr->strings.size() < 2 || alignerptr->strings.size() > 3) { return false; }
 	if (alignerptr->strings.size() == 2) {
 		create2DScene();
diff --git a/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.h b/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.h
index 7ac9627..9acd7b8 100644
--- a/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.h
+++ b/SequenceAlignmentVis/SequenceAlignmentVis/Visualizer.h
@@ -21,7 +21,7 @@ class Visualizer {
 	void globalAlignmentInit();
 	void freeEndsInit();
 	void localAlignmentInit();
-
+	void setPrevScene(Scene* prevScene) { this->prevScene = prevScene; }
 	void step();
 private:
 	bool stop = false;
@@ -44,6 +44,7 @@ class Visualizer {
 	Aligner* alignerptr;
 	Engine& engine;
 	FullDPTable* sceneTable;
+	Scene* prevScene;
 	Scene* scene;
 };