just a quick question am abit rubish with regex so thought I would post on here. The regex below is to validate a username. Must be between 4-26 characters long Start with atleast 2 letters Can only contain numbers and one underscore and one dot I have this so far, but isn't working <?php $username=$_POST['username']; if (!eregi("^([a-zA-Z][0-9_.]){4,26}$",$username)) { return false; } else { echo "username ok"; } ?> Thanks :)

php regex validation

just a quick question am abit rubish with regex so thought I would post on here. The regex below is to validate a username.

I have this so far, but isn't working

<?php

$username=$_POST['username'];

if (!eregi("^([a-zA-Z][0-9_.]){4,26}$",$username))
{
 return false;
}
else
{
 echo "username ok";
}

?>

Thanks :)