<SCRIPT LANGUAGE="JavaScript">
<!-- 
var form_total=0;
function CheckChoice(box)
{
if (box.checked == false)
	{ form_total -= eval(box.value); }
else 	{ form_total += eval(box.value); }
	document.myform.total.value = eval(form_total)+'元';
}
-->
</script>

<form method="POST" name="myform">
<table align=center width=300>
	<tr>
		<td height=50 colspan=2>目前有以下商品:</td>
	</tr>
	<tr>
		<td >AD运动衣350元</td><td width=30>
		<input type="checkbox" name="b1" value=350 onclick="CheckChoice(this);"></td>
	</tr>
	<tr>
		<td>NIKE运动背包220元</td><td width=30>
		<input type="checkbox" name="b2" value=220 onclick="CheckChoice(this);"></td>
	</tr>
	<tr>
		<td>乔丹运动鞋480元</td><td width=30>
		<input type="checkbox" name="b3" value=480 onclick="CheckChoice(this);"></td>
	</tr>
	<tr>
		<td colspan=2 align=right>花费总计: <input type="text" name="total" size=8 readonly value='0元' onFocus="this.blur();"></td>
	</tr>
</table>
</form>