Thanks what you added kind of showed me the way, I got the GUItexture to enable and the menu to disable AFTER i have pressed the "Play" button, The GUItexture is a loading screen image so i want that to display untill the next scene has fully streamed to 100% and then to automatically load the next scene, The problem im having is, Without me pressing the Play button, the game will just start anyway once its 100%, So how do i get it to wait untill i have pressed play before loading the scene? Here is were i am at the moment

if(GUI.Button (Rect ((Screen.width/2)-350,(Screen.height/2)-100,80,20), "Play")) {
   if (Application.GetStreamProgressForLevel(1) == 1)
      GetComponent(GUITexture).enabled = true;
      GetComponent(MainMenu).enabled = false;
      percentageLoaded = Application.GetStreamProgressForLevel(1) * 100;
      guiText.text = percentageLoaded.ToString();
    }  else {
           if (Application.GetStreamProgressForLevel(1) == 100)
            percentageLoaded = Application.GetStreamProgressForLevel(1) * 100;
            Debug.Log("Game started without pressing play");

      }

Uhmm... why do you still have the GUI button around all this? That would mean all that code is only executed once when you pressed the button...

Also a GUI.Button only works inside the OnGUI function...

Your code is now a total chaos and doesn't make any sense. Your indention is also wrong, maybe you want to check your brackets and logic...

I will edit my answer to show this code snippet in a full script.

Yeah its a mess first time trying to get things to work with streaming webplayer

var MenuMusic : AudioClip;
var buttonColor : Color = Color.red;
var BackgroundColor : Color = Color.green;
private var about : boolean = false;
private var chooseQuality : boolean = false;
function Start(){
   //Set Time Scale
   Time.timeScale = 1.0;
   //Find Cam
   transform.position = camera.main.transform.position;
   //Add Audio and Play It
   gameObject.AddComponent(AudioSource);
   audio.volume = .5;
   audio.clip = MenuMusic;
   audio.Play();
   audio.loop = true;
   //----------------------------------
}
function Update (){
   //Unlock Mouse
   Screen.lockCursor = false;
}
function OnGUI (){
   //Gui Color
    GUI.contentColor = buttonColor;
    GUI.backgroundColor = BackgroundColor;
    //Buttons

    if(GUI.Button (Rect ((Screen.width/2)-350,(Screen.height/2)-100,80,20), "Play")) 
    {
       if (Application.GetStreamProgressForLevel(1) == 1)
         GetComponent(GUITexture).enabled = true;
         GetComponent(MainMenu).enabled = false;
         percentageLoaded = Application.GetStreamProgressForLevel(1) * 100;
         guiText.text = percentageLoaded.ToString();
        }else{
            if (Application.GetStreamProgressForLevel(1) == 100)
                percentageLoaded = Application.GetStreamProgressForLevel(1) * 100;
                Debug.Log("Game started without pressing play");

        }      

   if(GUI.Button (Rect ((Screen.width/2)-350,(Screen.height/2)-50,80,20), "Options")) {
      //
      QualityOn();
   }
   if(GUI.Button (Rect ((Screen.width/2)-350,(Screen.height/2),80,20), "Controls")){
      AboutOn();

   }
   if(GUI.Button (Rect ((Screen.width/2)-350,(Screen.height/2) + 100,80,20), "Quit")){
      //Quit
      Application.Quit();
   }
   //Others
   if(about){
      GUI.color = Color.white;
      GUI.Label(Rect ((Screen.width/2) - 250,(Screen.height/2) - 100,500,500), GUIContent("MOVE: W-A-S-D \n\n" +"RUN: Shift \n\n" + "JUMP: Space \n\n"+"CROUCH: Ctrl \n\n"+"Shot: Mouse1 \n\n"
      + "AIM: Mouse2 \n\n" + "SWITCH WEAPONS: Mouse Wheel \n\n" + "FIRE MODE: Q \n\n" + "USE: E \n\n" + "LIGHT: F \n\n"));

      //Do not remove this

      //GUI.Label(Rect ((Screen.width/2) - 250,(Screen.height/2) + 250,500,500);
   }
   if(chooseQuality){
      about = false;
      //Give a Label
      GUI.Label(Rect ((Screen.width/2)-200,(Screen.height/2) - 100,100,40), "Quality Settings");

      if(GUI.Button (Rect ((Screen.width/2)-20,(Screen.height/2)-50,80,20), "High")){
         QualitySettings.currentLevel = QualityLevel.Fantastic;
         chooseQuality = false;
      }
      if(GUI.Button (Rect ((Screen.width/2)-120,(Screen.height/2)-50,80,20), "Medium")){
         QualitySettings.currentLevel = QualityLevel.Good;
         chooseQuality = false;
      }
      if(GUI.Button (Rect ((Screen.width/2)-220,(Screen.height/2)-50,80,20), "Low")){
         QualitySettings.currentLevel = QualityLevel.Fastest;
         chooseQuality = false;
      }

   }
}
function AboutOn (){
   about = true;
   chooseQuality = false;
   yield WaitForSeconds(10);
   about = false;
}
function QualityOn (){
   chooseQuality = true;
   about = false;
}

Basically how i have this set out, there are currently 3 scenes, Scene 0 = is splash screen transaction Scene 1 = Main menu Scene 2 = Game

The thing im having trouble with is the fact its steaming, So by the time the main menu has loaded the "Start" button wont load the game as its not fully streamed to 100% yet so im stuck looking at the main menu, So i want it to show a loading screen after i press the play button, once its at 100% the game scene loads in.