// jQuery version 1.6 or above use:
$("#myRadioID").prop("checked", true);
//jQuery versions below 1.6 use:
$("#myRadioID").attr('checked', 'checked');$("input:radio[name='thename']").each(function(i) {
this.checked = false;
});$("checkbox").is(":checked")$('#element').click(function() {
if($('#radio_button').is(':checked')) { alert("it's checked"); }
});
$('#myForm input').on('change', function() {
alert($('input[name=radioName]:checked', '#myForm').val());
});BY LOVE
if ($("input[name='Gender']:checked").length == 0)