Climbing Script

I have a climbing script, it is suppose to enable the character to climb but i cant get it to work... i have tried just about everything but still no climbing.. lol.. if anyone can help me and tell me where im going wrong it would be a massive bonus... The script is Unity script :

 public var MoveSpeed :float = 50;
 public var jumpSpeed : float = 55;                    
 public var MoveDirection = Vector3.zero;                            
 public var Gravity :float = 45;                               
 public var grounded : boolean = false;
  
 var on: boolean;
  
 var ObjectWall : Transform; 
 var ClimbSpeed : float = 200;    
 var NewDirections = Vector3.zero; 
 var Player : GameObject;   
 var localPosition : Vector3;   
 //var HeadBobOn: boolean = false;   
 //var headBobDistance : Vector3;   
 //var HeadBobSpeed : float = 3;   
 //var HeadBobTransform : Transform;   
 var Movement : boolean = true;   
 
 function Start (){ 
    Movement = true;  
    //HeadBobTransform = transform;  
 //   HeadBobOn = false;  
 //   localPosition = HeadBobTransform.localPosition; 
     }  
     
 function Update () {
     if( grounded ){
          MoveDirection = new Vector3(Input.GetAxis("Horizontal"), 0 , Input.GetAxis("Vertical"));                         
          MoveDirection = transform.TransformDirection(MoveDirection);                                  
          MoveDirection *= MoveSpeed ;                            
 //         HeadBobbing ();   
 }         
 
     if( grounded ) {          
         if(Input.GetKey(KeyCode.Space)){                
         
         MoveDirection.y = jumpSpeed;
 //                 HeadBobOn = false;
 }
 
         //if(grounded == true){         
         //   HeadBobOn = true;     
         //}} 
         
         if(Input.GetKey(KeyCode.W) || (Input.GetKey(KeyCode.UpArrow)))
         {     
 //        HeadBobOn = true;  
         } 
         if(Input.GetKey(KeyCode.LeftShift) && Input.GetKey(KeyCode.W))
         {      
         MoveSpeed = 400; 
         } 
         if ( on == true)
         {  
         if(Input.GetKey(KeyCode.C))
         {          
         MoveDirection = new Vector3( 0 , ClimbSpeed , 0);
         }
     }        
         if ( on == true){  
         if(Input.GetKey(KeyCode.V))
         {  
         MoveDirection = new Vector3( 0 , -ClimbSpeed , 0); 
         }
     }           
         MoveDirection.y -= Gravity * Time.deltaTime;                  
             var Controller = GetComponent(CharacterController);                   
                 var Flags = Controller.Move( MoveDirection * Time.deltaTime);                    
                     grounded = (Flags & CollisionFlags.CollidedBelow) !=0;                         
                 if (on == true){                            
                     grounded = (Flags & CollisionFlags.CollidedBelow) !=1;                         
                 }                         
                 if (on == false){                        
                     grounded = (Flags & CollisionFlags.CollidedBelow) !=0;                         
         }
     }
 }    
 /*    
 function HeadBobbing (){       
 
     if(HeadBobOn == true){ 
               
         var BobAmount = Mathf.Min(0.5, Mathf.Abs(Input.GetAxis("Vertical")) + Mathf.Abs(Input.GetAxis("Horizontal")));        
         var NexPositionX = localPosition.x + headBobDistance.x * Mathf.Sin(Time.time * HeadBobSpeed + Mathf.PI/2);          
     
         HeadBobTransform.localPosition.x = (localPosition.x * (1 + BobAmount)) + ( NexPositionX *(BobAmount));
                     
         var NexPositionY = localPosition.y + headBobDistance.y * Mathf.Sin(Time.time * HeadBobSpeed + Mathf.PI/2);          
         HeadBobTransform.localPosition.y = (localPosition.y * (1 - BobAmount)) + ( NexPositionY *(BobAmount)); 
     } 
 } 
 */        
 function OnTriggerEnter(other : Collider) {     
 
     on = true; 
     if(on == true){
     if( other.gameObject.tag == "rope" ){     
     Debug.LogWarning("You are in the trigger and are ready to climb");     
     }
     else
     { 
     on = false;  
         }
     }
 } 
 
 function OnTriggerExit(other : Collider) {    
 
     on = false;  
     if(on == false){     
     if( other.gameObject.tag == "rope" )    {
     Debug.LogWarning("You are out of the trigger");
     }
     else
     {        
     on = true;         
         }
     }
 }