Hi Kadafiz. Try this idea.
1. You can restrict the "userID text box" to make it accept only integers (0-9) using javascript. here's the code.
<HTML>
<HEAD>
<SCRIPT language=Javascript>
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && (charCode < 48 || charCode > 57))
return false;
return true;
}
</SCRIPT>
</HEAD>
<BODY>
<INPUT onkeypress="return isNumberKey(event)" type="text" name="userID" maxlength="9">
</BODY>
</HTML> 2. Restrict again your "userID textbox" to make it allow 9 digits only using maxlength
3. Now just define the last character which is the letter V. someting like
<?php
$id = $_POST['userID']."V";
?>
So you can now sure that the user will input only the required ID format.
I hope that could help you.