(SOLVED)validate date (mm/dd/yyyy

[Ninjakreborn]

I want to try and validate the date.  I wanted it to validate as (mm/dd/yyyy)
but the following code I tried, and that I created doesn't seem to work. I must be doing something wrong, can someone see a problem with it.
[code]<?php
$reg = "(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)\d\d";
if ($_POST['eventdate'] == "") {
$errorhandler .= "Event Date was left blank.<br />";
}
if (isset($_POST['eventdate'])) {
if (!ereg($reg, $_POST['eventdate'])) {
$errorhandler .= "Event date was not formatted properly.(mm/dd/yyyy)<br />";
}
}
?>[/code]