Ip地址，省份证等验证

<script language="javascript">
function checkIP()
{
obj=document.getElementById("ip").value
//ip地址
//var exp=/^(/d{1,2}|1/d/d|2[0-4]/d|25[0-5])/.(/d{1,2}|1/d/d|2[0-4]/d|25[0-5])/.(/d{1,2}|1/d/d|2[0-4]/d|25[0-5])/.(/d{1,2}|1/d/d|2[0-4]/d|25[0-5])$/;
//身份证
//var exp=//b(((?!/d/d/d)/d+|1/d/d|2[0-4]/d|25[0-5])(/b|/.)){4}/
//var exp=/^(/d{15}|/d{17}[x0-9])/
var exp=/^([/d]{15}|[/d]{18}|[/d]{17}[x|X])$/
var reg = obj.match(exp);
if(reg==null)
{
alert("IP地址不合法！");
}
else
{
alert("IP地址合法！");
}
}
</script>
请输入IP地址：<input type="text" id="ip">
<input type="button" onclick="checkIP()" value="验证">