验证ip地址，代码

Question

http://expert.csdn.net/Expert/topic/752/752259.xml?temp=.5410425

Answer 1

<SCRIPT LANGUAGE="JavaScript">
function isip(s){
   var check=function(v){try{return (v<=255 && v>=0)}catch(x){return false}};
  var re=s.split(".")
  return (re.length==4)?(check(re[0]) && check(re[1]) && check(re[2]) && check(re[3])):false
}var s="202.197.78.129";
alert(isip(s))
</SCRIPT>

Answer 2

<script>
function iponly (address) {
   var ipDomainPat=/^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/;
   var IPArray=address.match(ipDomainPat);
   if (IPArray!=null) 
      {for (var i=1;i<=4;i++) 
         {if (IPArray[i]>255) 
            {alert("IP地址输入不正确！");
     return false;}
}
       return true;}
   else 
     {alert("IP地址输入不正确！");
      return false;} 
}</script>
<input onchange=iponly(this.value)>

Answer 3

http://www.blueidea.com/bbs/newsdetail.asp?id=670192