GUI RPG box on keypress

Hey!

I have a problem that I hope I can get help with.

Basicly im trying to make a RPG type of game. I need it like when I press [z] on the keyboard it comes a popup window for skillpoints. I am using a GUI.Box now so that's fine, no custom texture needed. I'm coding in javascript and I would be glad if anybody tried to help me :). This is how my code looks now:

 #pragma strict
 
 var skillIsOpen : boolean = false;
 
 function OnGUI () {
     if(Input.GetKeyDown(KeyCode.Z)) {
         if(skillIsOpen == false) {
             skillIsOpen = true;
         }
         else {
             skillIsOpen = false;
         }
     }
     
     if(skillIsOpen == true) {
         GUI.Box(Rect(5, 5, 750, 750), "");
     }
 }

Thanks //Proximal-Pyro