Gui button runs the code without pressing

When i run my code and the GUI game over screen appears the GUI button that should restart the game clicks itself. void OnGUI() {

         if (gameOver) {
             GUI.backgroundColor = Color.clear;
             GUIStyle myStyle = new GUIStyle();
             myStyle.alignment = TextAnchor.MiddleCenter;
             myStyle.fontSize = 70;
             myStyle.normal.textColor = Color.white;
 
             GUIStyle myStyle1 = new GUIStyle();
             myStyle1.alignment = TextAnchor.MiddleCenter;
             myStyle1.fontSize = 40;
             myStyle1.normal.textColor = Color.white;
 
             GUI.Box (new Rect (0, 0, Screen.width, Screen.height), boi);
             GUI.matrix = Matrix4x4.TRS(new Vector3(GUIsF.x, GUIsF.y, 0), Quaternion.identity, GUIsF);
             GUI.Label (new Rect (0, -200, Screen.width, Screen.height), "Game Over!", myStyle);
             GUI.matrix = Matrix4x4.TRS(new Vector3(GUIsF.x, GUIsF.y, 0), Quaternion.identity, GUIsF);
             GUI.Button (new Rect (670, 300, RestartBTN.width, RestartBTN.height), RestartBTN);
             {
                 gameOver = false;
             }
 
 
             if(Input.GetKeyDown(KeyCode.Mouse0))
                 {
                 
             }
 
         }
 
     }