Button inside a window not responding!

I have a button inside a window. The button is showing, it is not responding to clicks! Here is the code:

void OnGUI()
    {
    	useGUILayout = true;
             GUI.skin = mainSkin;	
             if (showWindow)  GUI.DragWindow (2, new Rect (Screen.width / 2 - windowWidth / 2, Screen.height / 2 - windowHeight / 2, windowWidth, windowHeight), Yoyo, "NOTICE");
    } // end of OnGUI  	
    void Yoyo(int winID)
    {
            GUI.BringWindowToFront(winID); 
    	GUI.FocusWindow(winID);
    	if (GUI.Button (new Rect (windowWidth / 2 - buttonWidth / 2, windowHeight - buttonHeight + 50, buttonWidth, buttonHeight), "OKAYss")) 
    	{
                    // doesn't work :(
    		showWindow = false;
    		print ("got a click");
    	} // end of if
    	GUI.UnfocusWindow();
    } // end of Yoyo

Hi that’s the old system and don’t remember it much ,
the only thing that i remember is that if the button scale be negative it wont work ,

so check it out