test

jQuery.extend(jQuery.expr[':'],{
 'num-children' : function(element, index, matches,set) 
 {
  var count = 0;
  for (var node = element.firstChild; node; node= node.nextSibling) 
  {
   if(node.nodeType === 1) 
   {
    count ++;
   }
  }
  return count == matches[3];
 }
});