Enemy AI Animation

I stole this AI script from another forum page. Basically the enemy moves towards you when you are within a certain range. I want to know how to use the animator to play a walk animation when the character is moving, and an idle animation when the character is not. What parameters should I set in the animator? I am a beginner when it comes to java script. Thanks!

 public var target : Transform;
 public var moveSpeed : float = 3.0;
 public var attackRange : float = 10.0;
 public var stopRange : float = 2.0;
  
 function Start(){
     Patrol();
    animation.wrapMode = WrapMode.Loop;
    animation["idle"].layer = 1;
    animation["walk"].layer = 2;
    animation.Stop();
 }
  
 function Patrol(){
     while(true){
         if( AttackRangeCheck() ){ // target object is within range
             if( !StopRangeCheck() ){
                 transform.LookAt(target);
                 transform.Translate(Vector3.forward*Time.deltaTime*moveSpeed);
             }
         }
         yield;
     }
 }
  
 function AttackRangeCheck() : boolean{
     var distanceToTarget = Vector3.Distance(transform.position, target.position);
     if(distanceToTarget <= attackRange)
         return true;
     else
         return false;   
 }
  
 function StopRangeCheck() : boolean{
     var distanceToTarget = Vector3.Distance(transform.position, target.position);
     if(distanceToTarget <= stopRange)
         return true;
     else
         return false;   
 }