Menu Button help

I'm trying to add function to these Menu buttons. The Menu button shows all the buttons, and the Close one hides them again. I want the Credits button to pop up a new box when it's clicked.

 #pragma strict
 
 var showMoreGui = false;
 var showCredits = false;
         
 function OnGUI () {
     if (GUI.Button (Rect (650,300,100,20), "Open Menu"))
         showMoreGui = true;
    
     if (showMoreGui)  {
         (GUI.Button (Rect (650,350,100,20), "Play"));
         (GUI.Button (Rect (650,400,100,20), "Options"));

// this is the code that doesn't work, the credits button shows, but does nothing on clicking.

       {  if(GUI.Button (Rect (650,450,100,20), "Credits")){
           showCredits = true;
           
          if(showCredits) {
          (GUI.Box (Rect (600,300,100,100), "Credits Box"));}
       }    
      
                          
    if (GUI.Button (Rect (650,500,100,20), "Close"))
             showMoreGui = false;
     }}}