how can i know which radio button is selected via jquery

1$('input[name="name_of_your_radiobutton"]:checked').val();

1// jQuery version 1.6 or above use:  
2$("#myRadioID").prop("checked", true);
3 
4//jQuery versions below 1.6 use:
5$("#myRadioID").attr('checked', 'checked');

1$(document).ready(function(){
2  $('#submit_button').click(function() {
3    if (!$("input[name='name']:checked").val()) {
4       alert('Nothing is checked!');
5        return false;
6    }
7    else {
8      alert('One of the radio buttons is checked!');
9    }
10  });
11});

1if ($('input[name="radioName"]:checked', '#myForm').length) {
2	//Yes, it's checked!
3}