POSTVariables

    if ( isset( $_POST['firstname'] ) )
        $firstname = strip_tags( trim( $_POST['firstname'] ) );

    if ( isset( $_POST['lastname'] ) )
        $lastname = strip_tags( trim( $_POST['lastname'] ) );

    if ( isset( $_POST['phonenumber'] ) )
        $lastname = strip_tags( trim( $_POST['phonenumber'] ) );

    if ( isset( $_POST['username'] ) )
        $lastname = strip_tags( trim( $_POST['username'] ) );

    if ( isset( $_POST['userpassword'] ) )
        $lastname = strip_tags( trim( $_POST['userpassword'] ) );

    if ( isset( $_POST['emailaddress'] ) )
    {
        if ( preg_match( ‘/^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$/’, $_POST['$emailaddress'] ) )
            $emailaddress = trim($_POST['emailaddress']);
    }