Collider for transform.position?

Hello!

I have a problem. I have added to my simple EnemeyAI a simple movement, here is the script: var target : Transform; //the enemy's target var moveSpeed = 3; //move speed var rotationSpeed = 3; //speed of turning

 var myTransform : Transform; //current transform data of this enemy
 
 function Awake()
 {
     myTransform = transform; //cache transform data for easy access/preformance
 }
 
 function Start()
 {
      target = GameObject.FindWithTag("Player").transform; //target the player
 
 }
 
 function Update () {
     //rotate to look at the player
     myTransform.rotation = Quaternion.Slerp(myTransform.rotation,
     Quaternion.LookRotation(target.position - myTransform.position), rotationSpeed*Time.deltaTime);
 
     //move towards the player
     myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;
 
 
 }

But how can I say that my enemy is not walkin through walls anymore?