<html>
<head>
<script>
function validate()
{
p = document.getElementById("pan").value;
if(!p.match(/^([\w]{5})(\d{4})([\w]{1}$)/))
alert("Invalid");
else
alert("valid");
}
</script>
</head>
<body>
name of customer:<input type="text" id=cname></br>
name of bank:<input type="text" id=bname></br>
accno:<input type="text" id=acno name=acno></br>
pan no:<input type="text" id=pan name=pan></br>
<input type=submit value=Submit id=submit onclick="validate()">
</body>
</html>