[jQuery] [tooltip] "dynamic" extraClass

[muszek]

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?