Trouble with video

I'm trying to make a background video play when the player pauses the game, and I can't even get it to show up.

 public var PlayVid : MovieTexture;
 var isPlay;
 function Start()
 {
 PlayVid.loop = false;
 PlayVid.Stop();
 isPlay = false;
 }
 function OnGUI()
 {
 if(isPlay == true){
 PlayVid.loop = true;
 PlayVid.Play();
 }}
 function Update()
 {
 if(Input.GetKeyDown(KeyCode.Escape)){
    isPlay = true;
 }if(Input.GetKeyDown(KeyCode.N)){
    Start();
 }}

Does anyone have an idea why this won't play? I am using Unity Pro.