I'm trying to make sure some vars wrapped in a closure will be released for garbage collection when I'm done with them. I'm unsure weather setting them to undefined, or deleting them would be sufficient. Any thoughts? 

```
// run once for each photo, could be hundreds
$("img.photo").each( function(){
    // create the vars to put in the callback
    var photo = $(this);
    var tmp = new Image();

    // set the callback, wrapping the vars in its scope
    tmp.onload = (function(p,t){
      return function(){ 
        // do some stuff

        // mark the vars for garbage collection
        t.onload = ?
        t = ?
        p = ?
    })(photo, tmp)

    // set the source, which calls onload when loaded
    tmp.src = photo.attr("src")
})

```