try this:<script language="javascript">
function testIP(s)
{
var bGoodIP = false;
var re = /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/;
var a = s.match(re);
if (a)
{
if (a.length == 5)
{
var i;
for (i=1; i < a.length ; i++)
{
if (a[i] < 0 && a[i] > 255)
break;
} if (i == a.length)
bGoodIP = true;
}
} return bGoodIP;
}function checkInput()
{
var s = txtIP.value;
if(testIP(s))
alert('Good!');
else
alert('Bad!');
}
</script>
<input type="text" id="txtIP">
<input type="button" value="test iP" onclick="checkInput()">
function testIP(s)
{
var bGoodIP = false;
var re = /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/;
var a = s.match(re);
if (a)
{
if (a.length == 5)
{
var i;
for (i=1; i < a.length ; i++)
{
if (a[i] < 0 && a[i] > 255)
break;
} if (i == a.length)
bGoodIP = true;
}
} return bGoodIP;
}function checkInput()
{
var s = txtIP.value;
if(testIP(s))
alert('Good!');
else
alert('Bad!');
}
</script>
<input type="text" id="txtIP">
<input type="button" value="test iP" onclick="checkInput()">
if ( a[i]< 0 || a[i] > 255)
instead of
if (a[i] < 0 && a[i] > 255)
===>
var s = document.all("txtIP").value;