IP地址校验

 function validIp(fieldname,fielddesc){
     var value = $.trim($("#key_"+fieldname).val());
     var num =/^(\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 flag = num.test(value);
     if(!flag) {
         alert("IP地址输入不正确");
         return -1;
     }
     else
         return 0;
 }