jquery radio is check aval code example
Example: jQuery check a radio button
// jQuery version 1.6 or above use:
$("#myRadioID").prop("checked", true);
//jQuery versions below 1.6 use:
$("#myRadioID").attr('checked', 'checked');
// jQuery version 1.6 or above use:
$("#myRadioID").prop("checked", true);
//jQuery versions below 1.6 use:
$("#myRadioID").attr('checked', 'checked');