判断IP的正则表达式

print?var reg = /^(\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])$/; 
           if (!reg.test(RestrictIp)) { 
               $("#RestrictIp").focus(); 
               alert("请输入正确的IP地址！"); 
               return false; 
           } 

补充：web前端 , JavaScript ,