Registration script not working?

Registration script not working?

I created a registration script from bits and pieces that I have learned
from books on PHP. Unfornately, when testing it on local host (after
submitting test registration page), it displays the source of the PHP
script in browser. Is there something I'm doing wrong? Does any know any
open-source registration scripts?
Thanks
<?php
$submitted = $_POST["submitted"];
if ($submitted == 'yes') {
$firstName = mysql_real_escape_string($_POST["firstName"]);
$lastName = mysql_real_escape_string($_POST["lastName"]);
$eMail = mysql_real_escape_string($_POST["eMail"]);
$password = mysql_real_escape_string($_POST["password"]);
$confirmPassword = mysql_real_escape_string($_POST["confirmPassword"]);
// Kill script if input fields are blank
if ($firstName == '' or $lastName == '' or $eMail == '' or $password ==
'' or $confirmPassword == '')
{
die();
}
// Check if passwords match
if ($password != $confirmPassword)
{
die();
}
// Check if password is appropriat length
$passwordLength = strlen($password);
if ($passwordLength < 6 or $passwordLength > 30) {
die();
}
//////////////////////////
// Insert into database //
//////////////////////////
// Signup time in Unix Epoch
$time = time();
// Human readable date
$date = date("F jS, Y g:i:s A");
$sql = "INSERT into userInfo (firstName, lastName, password, eMail,
time, date) VALUES ('$firstName', '$lastName', '$password', '$eMail',
'$time', '$date')";
$sqlserver = "localhost";
$sqluser = "xxxxxx";
$sqlpassword = "xxxxxx";
mysql_connect($sqlserver, $sqluser, $sqlpassword) or die(mysql_error());
mysql_select_db("store");
// Check database if username already exists
$newEmail = $eMail;
$checkUsername = mysql_query("SELECT eMail FROM userinfo WHERE eMail =
'$newEmail'");
$numRows = mysql_num_rows($checkUsername);
if ($numRows > 0) {
die();
}
mysql_query($sql) or die(mysql_error());
mysql_close();
header("Location: http://store.viddir.com/login/");
exit;
}
else {
die();
}
?>