jQuery Forum

I have a section in my plugin that goes like this:

1. function(options, callback) {
2.         if($.isFunction(options)) {
3.               options = null;
4.               callback = options;
5.        }

EDIT: Its supposed to see if you didn't put the options parameter so it will cancel the options parameter and transfer the code to the callback parameter.
For some reason, its not working.
Could somebody help me?