1

var Destination = (0);

private var controller : FirstPersonController;

@script RequireComponent(FirstPersonController)

function Start ()

{

controller = GetComponent (FirstPersonController);

}

function OnControllerColliderHit (hit : ControllerColliderHit) {

if(Input.GetKeyUp("e"))

{
    //load level
    Application.LoadLevel(Destination);
}

}

Why does'nt this work?

2

I would use tags with gameobjects instead , and make a trigger in front of the door and use OnTriggerStay instead of colliding cause oncolliderhit is only called for one frame when the hit happens here is some exemplary code , add this to the trigger in front of the door (untested but it should give you the idea)

 var Destination ="MyLevel";
    function OnTriggerStay (other : Collider) {
    if(other.gameObject.tag =="Player"){
    if(Input.GetKeyUp("e"))
    Application.LoadLevel(Destination);   

    }
    }

You should also use level names for Application.LoadLevel , it takes away the confusion if you have a lot of levels