js校验

function checkIP2(sIPAddress)
{
     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])$/;
     var reg = sIPAddress.match(exp);
     var ErrMsg="你输入的是一个非法的IP地址段！\nIP段为：:xxx.xxx.xxx.xxx（xxx为0-255)！"    
     var Msg="你输入的是一个合法的IP地址段！"    
     if(reg==null)
     {
         alert(ErrMsg);
     }
     else
     {
         alert(reg);
     }
}