GetComponent Trolling Me?

I am making a Game in unity for an University assignment, and so far I have been doing good enough. I have made quite a lot of research every time i have come against an obstacle, and thus far I have solved all of my previous issues. However, this time, I'm having an issue with something I have already found the answer for, and I can't seem to find the mistake anywhere, no matter how hard I try to do so.

I am trying to access a variable from a different script, a Boolean to be specific, and while I have read how to do this, I can't seem to make it work.

The two scripts (not the final code, just what I was using to test if I could use the variable or not) are as follow:

 #pragma strict
 var crosshair : Texture2D;
 var welcomeMessage : WelcomeMessage;
 
 function Awake(){
 
     welcomeMessage = GetComponent(WelcomeMessage);
 }
 
 function Start () {
     
     
 }
 
 function Update () {
 
     welcomeMessage.messageDone = true; 
 }
 
 function OnGUI(){
     GUI.Label (Rect (Screen.width/2-250, Screen.height/2-150, 512, 512), crosshair);
 }



 
     #pragma strict
     var firstMessage : Texture2D;
     var secondMessage : Texture2D;
     var thirdMessage : Texture2D;
     var fourthMessage : Texture2D;
     var fifthMessage : Texture2D;
     var sixthMessage : Texture2D;
     var seventhMessage : Texture2D;
     var messageLifeSpan : float = 1.0f;
     var messageTimer : float = 0.0f;
     public var messageDone  : boolean = false;
     
     
     
     function Start () {
     
     }
     
     function Update () {
     //SetUp Timer to keep track of time.
         messageTimer += Time.deltaTime;
     }
     
         
     function OnGUI (){
     //wait 1 second, then show Message No1 for 8 seconds
         if (messageTimer > 1 && messageTimer < 9)
             GUI.Label (Rect (Screen.width/2-200, Screen.width/2-300, 512, 512), firstMessage);
     //wait another 2 seconds, then show message No2 for 12 seconds.
         else if (messageTimer > 11 && messageTimer < 27)
             GUI.Label (Rect (Screen.width/2-200, Screen.width/2-300, 512, 512), secondMessage);
     //wait another second, then show message No3 for 12 seconds.
         if (messageTimer > 29 && messageTimer < 45)
             GUI.Label (Rect (Screen.width/2-200, Screen.width/2-300, 512, 512), thirdMessage);
     //wait another second, then show message No4 for 12 seconds.
         else if (messageTimer > 47 && messageTimer < 63)
             GUI.Label (Rect (Screen.width/2-200, Screen.width/2-300, 512, 512), fourthMessage);
     //wait another second, then show message No5 for 8 seconds.
         else if (messageTimer > 65 && messageTimer < 73)
             GUI.Label (Rect (Screen.width/2-200, Screen.width/2-300, 512, 512), fifthMessage);
     //wait another second, then show message No6 for 12 seconds.
         if (messageTimer > 75 && messageTimer < 91)
             GUI.Label (Rect (Screen.width/2-200, Screen.width/2-300, 512, 512), sixthMessage);
     //wait another second, then show message No7 for 12 seconds.
         else if (messageTimer > 93 && messageTimer < 109)
             GUI.Label (Rect (Screen.width/2-200, Screen.width/2-300, 512, 512), seventhMessage);
     }

The error I am getting is: NullReferenceException: Object reference not set to an instance of an object Crosshair.Update () (at Assets/Scripts/Game/All Difficulties/All Levels/Crosshair.js:17)

And I cant understand why, I am using the format the Script Reference uses. Can anyone help me please?, I really need to be able to use variable from different scripts with ease.