function ValidateWarranties (chosen_name) {
			if (document.forms['warranties'].elements[chosen_name].checked == true) {
				for (i = 1; i <= 20; i++) {
					if (('vwitem'+i) != chosen_name) {
						if (document.forms['warranties'].elements['vwitem'+i])
							document.forms['warranties'].elements['vwitem'+i].checked = false;
					}
				}
			}
		}