Input type addClass not working in IE 6 or 7

Input type addClass not working in IE 6 or 7

Below is the code I have to add a class to radio buttons and checkboxes. This works in Firefox and Safari but not IE 6 or 7. Any help would be greatly appreciated.


$(document).ready(function(){

$("input[type=radio]").addClass("radio");
$("input[type=checkbox]").addClass("radio");

});