Null Reference Exeption??

So as some might know, I am making a minecraft command block as a project for school and I am getting a Null reference exeption for a random reason. I checked my whole scene to see if any thing had my script that had no assined vars and its clear! So is it in my script??

 #pragma strict
  
  //The string that is edited in the text field
  var Texture1 : Texture2D;
  var Texture2 : Texture2D;
  var Texture3 : Texture2D;
  var Impulse : boolean;
  var Chain : boolean;
  var Repeting : boolean;
  public var stringToEdit : String;
  var creativeMode : flyControllerScript;
  var survivalMode : MonoBehaviour;
  //The command as entered by the player
  public var command : String;
  public var command2 : String;
  public var command3 : String;
  public var command4 : String;
  var rigidbdy : Rigidbody;
  //Boolean to track when the player clicks to enable the text field
  public var clicked : boolean;
  //Boolean to track when the player has confirmed the command to enter
  public var shouldCheckCommand : boolean;
  
  function Start()
  { 
      survivalMode.enabled = true;     
       creativeMode.enabled = false;
      //Initialize variables
      stringToEdit = "/type in here";
      clicked = false;
      shouldCheckCommand = false;
      
  }
  function OnMouseDown ()
  {
      stringToEdit = "/type in here";
     clicked = true;
  }
  
  function Update()
  {
      
      //Check for the mouse click - the text field is invisible
      //if(Input.GetMouseButtonDown (0) && clicked == false)
      //{
          //Reset the string to default
        //  stringToEdit = "/type in here";
          //clicked = true;
      //}
      //Check for the Return/Enter key - the text field is visible
       if (Input.GetKeyDown(KeyCode.Return) && clicked == true)
      {
          command = stringToEdit; //Here is the key part - the string from the text field is assigned to the command variable
          command2 = stringToEdit; //Here is the key part - the string from the text field is assigned to the command variable
          clicked = false;
          shouldCheckCommand = true;
      }
      
      //Check if the player has confirmed the command entered
      if (shouldCheckCommand == true)
      {
          CheckCommand();
      }
  }
  
  function CheckCommand()
  {
      //Check which command was entered and take the appropriate action
      if (command == "/kill" || command == "/Kill")
      {
          Debug.Log("Kill the player");
          Application.LoadLevel(Application.loadedLevel);
          
          
          if(Repeting == true)
           {
              Debug.Log("Kill the player");
              Application.LoadLevel(1);          
           }
      }
      
      shouldCheckCommand = false;
      
           //Check which command was entered and take the appropriate action
      if (command2 == "/help"|| command2 == "/Help")
      {
          Debug.Log("The list of commands: /gamemode 0 (change to survival) /gamemode 1 (change to creative) /kill (kills player) /help (list of commands) More Commands comming soon");
            while (Repeting == true)
           {
               Debug.Log("The list of commands: /gamemode 0 (change to survival) /gamemode 1 (change to creative) /kill (kills player) /help (list of commands) More Commands comming soon");
           }
 
      }
      
      shouldCheckCommand = false;
      
      
      if (command3 == "/gamemode 0"|| command3 == "/gamemode survival")
      {
          Debug.Log("Gamemode is now survival");
          creativeMode = GetComponent(flyControllerScript); 
            survivalMode.enabled = true;
            creativeMode.enabled = false;
            rigidbdy.GetComponent.<Rigidbody>().isKinematic = true;
          rigidbdy.GetComponent.<Rigidbody>().detectCollisions = true;
            
            if (Repeting == true)
           {
              Debug.Log("Warning Code has protected unity from crashing!");
           }
 
      }
      
      shouldCheckCommand = false;
      
           if (command4 == "/gamemode 1"|| command4 == "/gamemode creative")
      {    
          
          Debug.Log("Gamemode is now Creative");
          creativeMode = GetComponent(flyControllerScript); 
            creativeMode.enabled = true;
            survivalMode.enabled = false;
          rigidbdy.GetComponent.<Rigidbody>().isKinematic = true;
          rigidbdy.GetComponent.<Rigidbody>().detectCollisions = false;
            
            
            if (Repeting == true)
           {
              Debug.Log("Warning Code has protected unity from crashing!");
 
           }
 
      }
      
      shouldCheckCommand = false;
  }
       
  function OnGUI()
  {
      if(clicked == true)
      {    
          stringToEdit = GUI.TextField (Rect (0, 100, 200, 200), stringToEdit, 200);
          GUI.Button(Rect(0, 0, 200, 50), "Command Block Interface");
          if (GUI.Button(Rect(0, 300, 200, 50), "Impulse")){
              GetComponent.<Renderer>().material.mainTexture = Texture1;
              Impulse = true;
          }
          if (GUI.Button(Rect(0, 350, 200, 50), "Chain")){
              GetComponent.<Renderer>().material.mainTexture = Texture2;
              Chain = true;
          }
          if (GUI.Button(Rect(0, 400, 200, 50), "Repeting")){
              GetComponent.<Renderer>().material.mainTexture = Texture3;
              Repeting = true;
          }
         
         if (GUI.Button(Rect(0, 500, 200, 50), "Done")){
              clicked = false;
          }
      }
  }
 

Please help !