You have to setup prettyPhoto first (because of how the plugin is written, unfortunately), like this:
$(document).ready(function(){
$.fn.prettyPhoto(); //usually $("a[rel^='prettyPhoto']").prettyPhoto();
$.prettyPhoto.open('http://www.microdual.com/assets/images/newsletters/doublehosting.jpg','Test','Test desc');
});
You can see in the source that functions like $.prettyPhoto.open()
are defined by running `$.
The other issue is the plugin seems to have an issue with caller context introduced in jQuery 1.4.4, it works fine with 1.4.3 (you can test it here). This has been reported on the forums, hopefully the author will address it soon.