How to clear asp.net fileupload control using javascript?

Note: The below code will works in both IE and Firefox.

function Clear(elem)
{
var who =document.getElementById(elem.id);
who.value="";
var who2= who.cloneNode(false);
who2.onchange= who.onchange;
who.parentNode.replaceChild(who2,who);
document.getElementById(elem.id).select();
}