Why do I get a Parsing Error using this script?

 var walkSpeed: float = 7; // regular speed
 var crchSpeed: float = 3; // crouching speed
 var runSpeed: float = 20; // run speed
  
 private var chMotor: CharacterMotor;
 private var ch: CharacterController;
 private var tr: Transform;
 private var height: float; // initial height
  
 function Start(){
     chMotor = GetComponent(CharacterMotor);
     tr = transform;
     ch = GetComponent(CharacterController);
     height = ch.height;
 }
  
 function Update(){
  
     var h = height;
     var speed = walkSpeed;
     
     if (ch.isGrounded && Input.GetKey("left shift") || Input.GetKey("right shift")){
         speed = runSpeed;
     }
     if (Input.GetKey("c")){ // press C to crouch
         h = 0.5 * height;
         speed = crchSpeed; // slow down when crouching
     }
     chMotor.movement.maxForwardSpeed = speed; // set max speed
     var lastHeight = ch.height; // crouch/stand up smoothly 
     ch.height = Mathf.Lerp(ch.height, h, 5*Time.deltaTime);
     tr.position.y += (ch.height-lastHeight)/2; // fix vertical position
 }