jquery proxy

slice = Array.prototype.slice,
// Bind a function to a context, optionally partially applying any
    // arguments.
    proxy: function( fn, context ) {
        if ( typeof context === "string" ) {
            var tmp = fn[ context ];
            context = fn;
            fn = tmp;
        }

        // Quick check to determine if target is callable, in the spec
        // this throws a TypeError, but we will just return undefined.
        if ( !jQuery.isFunction( fn ) ) {
            return undefined;
        }

        // Simulated bind
        var args = slice.call( arguments, 2 ),
            proxy = function() {
                return fn.apply( context, args.concat( slice.call( arguments ) ) );
            };

        // Set the guid of unique handler to the same of original handler, so it can be removed
        proxy.guid = fn.guid = fn.guid || proxy.guid || jQuery.guid++;

        return proxy;
    },