<script>function checkIP(str)
{
ss=str.split(".");
for(a=0;a<ss.length;a++)
if ((ss[a]>255)|(ss[a]<0)) return false;
return true;
}
var str=new String("202.194.86.500");
document.write(checkIP(str));
</script>
{
ss=str.split(".");
for(a=0;a<ss.length;a++)
if ((ss[a]>255)|(ss[a]<0)) return false;
return true;
}
var str=new String("202.194.86.500");
document.write(checkIP(str));
</script>
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>
<!--
function HW_CheckIP (str)
{
ip='(25[0-5]|2[0-4]\\d|1\\d\\d|\\d\\d|\\d)';
ipx=ip+'\\.';
isIPaddress=new RegExp('^'+ipx+ipx+ipx+ip+'$');
if (isIPaddress.test(str)){alert("Yes");}
else{alert("NO");}
}
HW_CheckIP("111.1.1.1")
HW_CheckIP("111.256.1.1")
HW_CheckIP("111..1.1")
//-->
</SCRIPT>
function checkip(ip)
{
var re = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/;
if(arr = ip.match(re)) {
for(var i=1;i<arr.length;i++)if(parseInt(arr[i])>255){alert(ip+" 不正确");return;}
alert(ip+" 正确");
}
else alert(ip+" 不正确");
}
</script>
<input type=text name=ip>
<input type=button onclick="checkip(document.all.ip.value)" value="CheckIP">