This is related to the tooltip plugin - http://docs.jquery.com/Plugins/Tooltip .
I've written a short PHP helper that displays tooltips. Simple $myHelper->tooltip('text'); displays a nice icon and stores the text to be printed out right before </body> tag. Works as expected. Now... the problem is that sometimes I'd like to give a tooltip a custom class. It's handled via extraClass option and works for me if I hard-code it in my js file. My solution: assign that right-before-</ body> div a custom class and read this attrib's content in .js file. My current JS code: $(document).ready(function(){ $(".tip").tooltip({ bodyHandler: function() {return $($(this).attr("href")).html();}, delay: 0, showURL: false, }); }); I tried doing this (keep in mind that I'm new to jquery and js in general): $(document).ready(function(){ $(".tip").tooltip({ bodyHandler: function() {return $($(this).attr("href")).html();}, extraClass: function() {return $($(this).attr("href")).attr ("class");}, delay: 0, showURL: false, showBody: " - ", }); }); ... but firebug complains: (classNames || "").split is not a function curCSS()()jquery.min.js (line 21) trigger()()jquery.min.js (line 25) nodeName()()jquery.min.js (line 20) filter()()jquery.min.js (line 12) trigger()()jquery.min.js (line 25) save()hotels.js (line 29) ready()()jquery.min.js (line 26) trigger()()jquery.min.js (line 25) [Break on this error] for(var value=object[0];i<length&&callba...jQuery (elem).is(":visible"))getWH();else (jquery.min.js (line 21)) How shold my my extraClass line look like?