These lines

if (! ereg('[A-Za-z0-9_-]+\@[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+', $Email))
{
header("Location: email_error.html");
exit;
if (strlen($password) == 0 )
}
header("Location: error_password.html");
exit;

should be

if (! ereg('[A-Za-z0-9_-]+\@[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+', $Email))
{
header("Location: email_error.html");
exit;
}
if (strlen($password) == 0 )
{
header("Location: error_password.html");
exit;
}

__________________

Register/Login Script
Do you use a Password Protected Directory? Need a way to allow users to make their own account, try my .htaccess Login Script