Pasue Game and then Ask for input to unpasue

Hello what im trying to do is pause the game and then ask for input to un-pause it basically. I have worked this out to a degree but now it give a fatal error and kills the game. So this is my ongui function to display the input needed

 function OnGUI()
 {
     
     var m : int;
     m = meters; 
     GUI.Box(new Rect(0,0,Screen.width/4,Screen.height/5), "Jump ");
         GUILayout.Label("");
         GUILayout.Label("Alt: " + m + "m");
         
         while(sliderGUI == true)
         {
             
             GUI.Box(new Rect(0,0,Screen.width/4,Screen.height/5), "");
             GUILayout.Label("");
             GUILayout.Label("");
             GUILayout.Label("Chosices");
             GUILayout.Label("Error: ");
             GUILayout.Label("");
             GUILayout.Label("Press A to do something");
             GUILayout.Label("");
             GUILayout.Label("Press X Hope for the best");
             
             
             
             if(Input.GetKeyDown(KeyCode.A))
             {
                 
                 sliderGUI = false;
                 pause = false;
                 
             }else
             {
                 pause = true;
             }
             
             
             
             if(pause == true)
             {
                 //pause game
                 Time.timeScale = 0;
             }else
             {
                 //resume game
                 Time.timeScale = 1;
             }
         
         }
         
 }

And then this is where I call this function somewhat by makeing the sliderGUI boolean true.

 function SliderHangup()
 {
     
     this.animation.CrossFade("SliderHang");
     
     this.rigidbody.drag = 0.9f;
     
     Debug.Log("Animation time " + this.animation.clip.length);
     yield WaitForSeconds(2);
     
     sliderGUI = true;
     
     
 
 }