Stop animation after playing once

I'm using RaycastHit to script a door opening animation when my character comes within a few feet of the door. How do I get the animation (of door sliding out of the way) to play only one time.

Right now, once I'm within the specified distance, the door animation keeps playing over and over (so keeps opening and closing until I move back out of distance).

Animation simply has door keyed to normal position at 0 frames, and then position.y made negative so door slides into ground at 30 frames. And here's the script I'm using:

var rayCastLength = 10;

function Update ()

{ var hit:RaycastHit;

//check if we're colliding
if(Physics.Raycast(transform.position, transform.forward, hit, rayCastLength))
//with a door - need to add the 'collider' in this code since using Raycast instead of just collision
if(hit.collider.gameObject.tag == "door")
    //open the door



Setting ClampForever wrapMode on your door animation should do the trick.