Edit in JSFiddle

$(document).ready(function() {
   $('#btnStatus').click(function(){
      var isChecked = $('#rdSelect').is(':checked');
      alert(isChecked);
   });
});

<b> <input type="radio" id="rdSelect"/> Select/Deselect </b>
<br/><br/>
<input type="button" id="btnStatus" value="Get Radio Button status" />