Keep tapping button to do certain action

I'm using the first person controller and i have a running script and everything but how do i make it so whenever i am tapping W i run, Like the game receiver. #pragma strict

 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
  
 public var slideSpeed: float = 20; // slide speed
 private var isSliding : boolean = false;
 private var slideForward : Vector3; // direction of slide
 private var slideTimer : float = 0.0;
 public var slideTimerMax : float = 2.5; // time while sliding
  
 function Start()
 {
     chMotor = GetComponent(CharacterMotor);
     tr = transform;
     ch = GetComponent(CharacterController);
     height = ch.height;
 }
  
 function Update()
 {
     var h = height;
     var speed = walkSpeed;
  
     // - run and crouch -  
     if (ch.isGrounded && Input.GetKey("left shift") || Input.GetKey("right shift")) // press Shift to run
     {
        speed = runSpeed;
     }
     if (Input.GetKey("c")) // press C to crouch
     {
        h = 0.5 * height;
        speed = crchSpeed; // slow down when crouching
     }  
  
     // - slide -   
     if (Input.GetKeyDown("f") && !isSliding) // press F to slide
     {
        slideTimer = 0.0; // start timer
        isSliding = true;
        slideForward = tr.forward;
     }
     if (isSliding)
     {
        h = 0.5 * height; // height is crouch height
        speed = slideSpeed; // speed is slide speed
        chMotor.movement.velocity = slideForward * speed;
  
        slideTimer += Time.deltaTime;
        if (slideTimer > slideTimerMax)
        {
          isSliding = false;
        }
     }  
  
     // - apply movement modifiers -    
     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
     
     }

That is the code i am using. Also if someone can give me a link that teaches Javascript/Unityscript and/or C# without all the i'm going to show you how to start up unity and end the video in 2 minutes, that would help me out alot