change
});
$(document).ready(function () {
$('.smallTabsHeader a').pluginbutton();
});
to
})(jQuery); //<-- ADD THIS
$(document).ready(function () {
$('.smallTabsHeader a').pluginbutton();
});
This is needed because, you need to call the anonymous function that you created with
(function($){
and notice that it expects an argument that it will use internally as $, so you need to pass a reference to the jQuery object.
Additionally, you will need to change all the this. to $(this)., except the first one, in which you do return this.each
In the first one (where you do not need the $()) it is because in the plugin body, this holds a reference to the jQuery object matching your selector, but anywhere deeper than that, this refers to the specific DOM element, so you need to wrap it in $().
Full code at http://jsfiddle.net/gaby/NXESk/