Erm, why this don`t work, iv used similar code like this for my site many times..butnow dont work..
HTML
<div><span>a</span><input type='hidden' /> <input type='button' onClick='Remove(event)' />
JQuery
function Remove(e){
e.preventDefault();
$(this).closest('div').remove();
}
Looks like $(this) is not my button. I tested with alert($(this).val()) and nothing heppend.

How about adding a class to the button element and bind a handler to the button
Code:
In such cases you can use delegated events. See below,