proxy = function() {
    return fn.apply( thisObject || this, arguments );
};

Taken from http://code.jquery.com/jquery-latest.js. If the ES5 Function.prototype.bind is available it should use that native function instead.

 
if (fn.bind) {
    proxy = fn.bind( thisObject || this ) 
} else {
    proxy = function() {
        return fn.apply( thisObject || this, arguments );
    };
}