diff --git a/models/SimpleUI2.model b/models/SimpleUI2.model
index bf240ca..da3b0c3 100644
--- a/models/SimpleUI2.model
+++ b/models/SimpleUI2.model
@@ -1,5 +1,5 @@
 native channel ScreenUpdate {
-	in screen(curSc: Json, update(nextSc)) = nextSc
+	in screen(curSc: Json, update(curSc, nextSc)) = nextSc
 }
 
 native channel SetVisible(wid: Str) {
diff --git a/src/main/java/com/example/test/rest_controllers/ElementsController.java b/src/main/java/com/example/test/rest_controllers/ElementsController.java
new file mode 100644
index 0000000..354b46a
--- /dev/null
+++ b/src/main/java/com/example/test/rest_controllers/ElementsController.java
@@ -0,0 +1,22 @@
+package com.example.test.rest_controllers;
+
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/elements")
+public class ElementsController {
+	
+	@PostMapping("/buttonPressed")
+	public void buttonPressed(@RequestParam("id") String id) {
+		System.out.println("button " + id + " pressed!");
+	}
+	
+	@PostMapping("/buttonReleased")
+	public void buttonReleased(@RequestParam("id") String id) {
+		System.out.println("button " + id + " released!");
+	}
+	
+}
diff --git a/src/main/java/com/example/test/services/ButtonService.java b/src/main/java/com/example/test/services/ButtonService.java
new file mode 100644
index 0000000..0b39ce0
--- /dev/null
+++ b/src/main/java/com/example/test/services/ButtonService.java
@@ -0,0 +1,19 @@
+package com.example.test.services;
+
+import org.springframework.stereotype.Service;
+
+import models.dataConstraintModel.ResourcePath;
+import models.dataFlowModel.DataTransferChannel;
+import simulator.Resource;
+import simulator.Simulator;
+import simulator.interfaces.NativeSender;
+
+@Service
+public class ButtonService extends NativeSender{
+
+	public ButtonService(Simulator simulator, DataTransferChannel channel, ResourcePath resourcePath,
+			Resource resource) {
+		super(simulator, channel, resourcePath, resource);
+	}
+	
+}
diff --git a/src/main/resources/static/simulator_ws.js b/src/main/resources/static/simulator_ws.js
index 52f151e..4e932f2 100644
--- a/src/main/resources/static/simulator_ws.js
+++ b/src/main/resources/static/simulator_ws.js
@@ -1,3 +1,4 @@
+const apiUrl = "http://localhost:8080/api"
 let socket = new WebSocket("ws://localhost:8080/ws");
 
 socket.onmessage = function(event) {
@@ -8,7 +9,7 @@
     console.log(method);
     switch(method){
         case "updateHtml":
-            put_htmls(json_data.elements);
+            put_htmls(json_data.data);
             break;
     }
 
@@ -18,7 +19,15 @@
 
 function put_htmls(elements){
     let container = document.getElementById("container");
-    for(const elem of elements){
+    let addElems = elements.add;
+    let delElems = elements.delete;
+    for(const id of delElems) {
+        let elem = document.getElementById(id);
+        if(elem) {
+            elem.parentNode.removeChild(elem);
+        }
+    }
+    for(const elem of addElems){
         let id = elem.id;
         let type = elem.type;
         let styles = elem.styles;
@@ -28,14 +37,42 @@
             let value = styles[prop];
             style += `${prop}: ${value};`
         }
+        let style_attribute = Object.keys(styles).lenget > 0 ? `style="${style}"` : "";
         switch(type){
             case "button":
-                container.insertAdjacentHTML("beforeend", `<button id="${id}" style="${style}">${text}</button>`)
+                container.insertAdjacentHTML("beforeend", `<button id="${id}" ${style_attribute}">${text}</button>`)
+                let button = document.getElementById(id);
+                button.addEventListener("mousedown", buttonPressed);
+                button.addEventListener("mouseup", buttonReleased);
                 break;
         }
     }
 }
 
+function buttonPressed(event){
+    const data = {id: event.target.id};
+    const formBody = new URLSearchParams(data);
+    fetch(`${apiUrl}/elements/buttonPressed`, {
+        method: 'POST',
+        headers: {
+            'Content-Type': 'application/x-www-form-urlencoded',
+        },
+        body: formBody.toString()
+    });
+}
+
+function buttonReleased(event) {
+    const data = {id: event.target.id};
+    const formBody = new URLSearchParams(data);
+    fetch(`${apiUrl}/elements/buttonReleased`, {
+        method: 'POST',
+        headers: {
+            'Content-Type': 'application/x-www-form-urlencoded',
+        },
+        body: formBody.toString()
+    });
+}
+
 socket.onopen = function(event) {
     console.log("open socket");
 }