if this.unchecked jquery code example
Example: jquery checkbox unchecked
$("input:radio[name='NAME']:radio[value='VALUE']").attr("checked",true);
$("input:radio[name='NAME']").removeAttr("checked");
$("input:radio[name='NAME']:radio[value='VALUE']").attr("checked",true);
$("input:radio[name='NAME']").removeAttr("checked");