How to Unchecked RadioButton

use followin code RadioButton Unchecked Problem is not occur
work in both html or asp.net
same code for both


   $(document).ready(function () {
            $("input[type='radio']").mousedown(function (e) {
                if ($(this).attr("checked") == true) {
                    setTimeout("$('input[id=" + $(this).attr('id') + "]').removeAttr('checked');", 200);
                }
                else {
                    return true
                }
            });
        });