java script problems

i am making a game and i am having scripting problems i want to make it so when var bullet is touching var self level 2 loads my problem is:

Assets/scripts/touch.js(3,18): BCE0022: Cannot convert ‘UnityEngine.Quaternion’ to ‘UnityEngine.Transform’.

my code is:

var bullet : Transform;

var self : Transform;

self = transform.rotation;

transform.rotation = Quaternion.identity;

function update (){

if (self){ Application.LoadLevel(2); }

}

//please post a full script

put the

transform.rotation = Quaternion.identity

in any function. In Update, Start or Awake