So in real browsers, if you bind something to an element's click event, your handler returns false in order to stop the even bubbling. It's fairly simple.
In jQuery, for example,

$('a.thingy').click(function(){
   // do something
   return false'
});

This essentially hijacks the click and replaces the default behaviour with whatever you code.
On form elements, it's the same.

$('input[type=radio]').change(function(){
    // do something
    return false;
});

The catch here is that you don't need to return false because you don't need to prevent an action such as an anchor's page location change. This caught me out because in real browsers it doesn't matter, but in Internet Explorer the event fires for every element in the radio group, or the existing and new options in a select box. Returning false, in essence, tells IE to move on to the next element's event. So don't do it. Either return true or - simpler - just don't return anything. Then IE will behave like the rest of the world.