I am using the code listed below to simulate a computer terminal (think Black Ops computer) however whenever I transfer the game to my other computer which has a larger screen size/resolution, the GUI gets mucked up. I was thinking of displaying the GUI in absolute pixels however I am unsure as to how I can do that with my script. Thanks in advance!

var visible;
var controlTexture : Texture2D;
var gameCode : String = "1234";
var stringToEdit : String;
var buttonMessage : String = "Enter Command";
var pladas : String = "/test";
var practice : String = "/practice";
var zombies : String = "/zombies";
var instructions : String = "/help";
function OnGUI(){
  if( visible )
  {
   stringToEdit = GUI.TextField (Rect (400, 500, 70, 25), stringToEdit, 10); 
   if(stringToEdit == "1234"){
      buttonMessage = "Begin Game";
   }else
   if(stringToEdit == "/help"){
    buttonMessage = "Instructions";
   }else
   if(stringToEdit == "/zombies"){
      buttonMessage = "Unleash the Horde!";
   }else
   if(stringToEdit == "/test"){
      buttonMessage = "Secret";
   }else
   if(stringToEdit == "/practice"){
    buttonMessage = "Begin Training";
   }else{
      buttonMessage = "Enter Command";
   }
   if(GUI.Button(Rect(500, 500, 135, 25), buttonMessage) && stringToEdit == "1234"){
      Application.LoadLevel (1);
   }else 
   if(GUI.Button(Rect(500, 500, 135, 25), buttonMessage) && stringToEdit == "/zombies"){
    Application.LoadLevel ("Zombies");
   }else
   if(GUI.Button(Rect(500, 500, 135, 25), buttonMessage) && stringToEdit == "/test"){
      Application.LoadLevel ("Test");
   }else
   if(GUI.Button(Rect(500, 500,135, 25), buttonMessage) && stringToEdit == "/help"){
    Application.LoadLevel ("Walkthrough");
   }else
   if(GUI.Button(Rect(500, 500, 135, 25), buttonMessage) && stringToEdit == "/practice"){
    Application.LoadLevel ("Practice");
   }
}
}
function Update(){
  if(Input.GetKeyDown(KeyCode.M))
  {
    visible = !visible;
  }
}