loop through radio buttons

  		function return_agent(theForm) {
				var radioSelected = false;
				for (i = 0;  i < theForm.agent_id.length;  i++)
				{
				if (theForm.agent_id[i].checked)
				radioSelected = true;
				}
				if (!radioSelected)
				{
				alert("Please select one of the agents is selected.");
				return (false);
				}