add more fields mail in user registration

This code works but I'm just wondering about the $message['id'] and 'user_register_pending_approval_admin'. I want to use profile module to add another information in registration. I want to add !fullname field to show in user's emailed information. Can you give me more efficient code than this?

<?php
/**
* Version: Drupal 6.x
*
* Implementation of hook_form_alter()
* Alter the user_admin_settings form to display the added email tokens
**/

function modifyMail_form_alter(&$form, $form_state, $form_id){

    if ($form_id == "user_admin_settings") {
        $form['email']['pending_approval']['#description'] .= ' Additional variables are: !first, !middle, !last.';
    }

}

/**
* Implementation of hook_mail_alter().
*
* This hook is being used to get the full name of the registrant and replace
* the variables within emails (!first, !middle, !last) with the registrant's
* first, middle and last name as captured by the registration form and stored
* in profiles_values table.
*
* NOTE: Remember to add the new variables (!first, !middle, !last) to the email subject line and body in
* administration section > user settings > User e-mail settings > Welcome...
*/

function modifyMail_mail_alter(&$message) {
global $base_root;
global $base_path;
global $user;

    switch($message['id']) {
        case 'user_status_activated':
            //NOTIFY ADMINS OF ACCOUNT ACTIVATION
            $bcc = variable_get('modifyMail_addresses', '');
            if ($bcc != '') $message['headers']['bcc'] = $bcc;

            break;
        case 'user_register_pending_approval_admin':
            //get new registrant's username and id
            $sql2 = 'SELECT uid,name FROM {users} WHERE uid=(SELECT MAX(uid) FROM {users})';
            $result2 = db_query($sql2);
            $row2 = db_fetch_object($result2);
          
            $uid = $row2->uid;
            $name = $row2->name;
          
            //get new registrant's fullname name
            //get the profile fields using user id
            $sql = "SELECT fid,value FROM {profile_values} WHERE uid='%s' AND (fid=1 OR fid=2 OR fid=3)";
            $result = db_query($sql, $uid);
          
            //create array to hold values
            $new_variables = array();
  
            //loop through query result
            while ($row = db_fetch_object($result)) {
                //switch on the field id (fid) of the result
                //fid 1 is first name, fid 2 is last name, fid 3 is middle name
                switch ($row->fid) {
                    case 1:
                        $new_variables += array('!first' => $row->value);
                        break;
                    case 2:
                        $new_variables += array('!last' => $row->value);
                        break;
                    case 3:
                        $new_variables += array('!middle' => $row->value);
                        break;          
                }
            }
            //check the middle name and tweak for full name display
            if (isset($new_variables['!middle'])) {
                $new_variables['!middle'] .= " ";
            }else{
                $new_variables['!middle'] = '';
            }
          
            //create array of replacement vars
            $replace = array(
                        '!fullname' => $new_variables['!first'] . " " . $new_variables['!middle'] . $new_variables['!last'],
                        '!site'        => variable_get('site_name', 'Your Site Name'),
                        '!username'    => $name
            );
          
            $email_list = variable_get('modifyMail_addresses', variable_get('site_mail',ini_get('sendmail_from')));

          
            $message['subject'] = _user_mail_text('pending_approval_admin_subject', $message['language'], $variables);
            //drupal_set_message('message subject is:'.$message['subject']);

            $message['subject'] = strtr($message['subject'], $replace);
            $message['body'][0] = $replace['!fullname'] . " registered as username: " . $replace['!username'] . ". \n\nAuthorize the registration at: " . $base_root . $base_path . "user/" . $uid . "/edit \n\nReview ".$replace['!fullname'] . "'s profile at: ".$base_root.$base_path."user/".$uid;
            //drupal_set_message("fullname is:".$replace['!fullname']." and body is:".$message['body'][0]);
            $message['to'] = $email_list;
          
        break;
        default :
        //identify to whom the email is being sent
        $email = $message['to'];
      
        //get user id from db using email address
        $sql2 = "SELECT uid FROM {users} WHERE mail='%s'";
        $result2 = db_query($sql2, $email);
        $row2 = db_fetch_object($result2);
      
        $uid = $row2->uid;
      
        //get the profile fields using user id
        $sql = 'SELECT fid,value FROM {profile_values} WHERE uid=%d AND (fid=1 OR fid=2 OR fid=3)';
        $result = db_query($sql, $uid);
      
        //create array to hold values
        $new_variables = array();
      
        //loop through query result
        while ($row = db_fetch_object($result)) {
            //switch on the field id (fid) of the result
            //fid 1 is first name, fid 2 is last name, fid 3 is middle name
            switch ($row->fid) {
                case 1:
                    $new_variables += array('!first' => $row->value);
                    break;
                case 2:
                    $new_variables += array('!last' => $row->value);
                    break;
                case 3:
                    $new_variables += array('!middle' => $row->value);
                    break;          
            }
        }
  
        //check for middle name existence
        if (!isset($new_variables['!middle'])) { $new_variables['!middle'] = ''; }
  
        //replace placeholders (!first, !last, !middle) in email
        //with corresponding new variables
        $message['subject'] = strtr($message['subject'], $new_variables);
        $message['body'][0] = strtr($message['body'][0], $new_variables);
      
        break;
    }
}


/**
* Implementation of hook_help().
*
* Throughout Drupal, hook_help() is used to display help text at the top of
* pages. Some other parts of Drupal pages get explanatory text from these hooks
* as well. We use it here to provide a description of the module on the
* module administration page.
*/
function modifyMail_help($section) {
  switch ($section) {
    case 'admin/modules#description':
      // This description is shown in the listing at admin/modules.
      return t('The modfiyMail module adds variables available to the system-generated emails.');
  }
}

/**
* Valid permissions for this module
* @return array An array of valid permissions for the modifyMail module
* Sets the permissions
*/

function modifyMail_perm() {
    return array('administer modifyMail');
}


/*
The following adds a field for entering admin emails
to notify that a new member is requesting registration.
These should be the emails of admins that can approve/deny the request
*/
function modifyMail_admin() {
    $form['modifyMail_addresses'] = array (
        '#type'                => 'textarea',
        '#title'            => t('Notify addresses'),
        '#default_value'    => variable_get('modifyMail_addresses', variable_get('site_mail',ini_get('sendmail_from'))),
        '#description'        => t('Enter each recipient&rsquo;s email address on a new line or place a comma between addresses. The email addresses entered will receive new member registration notifications.'),
        '#required'            => TRUE
    );
    return system_settings_form($form);
}

/*
If you want to notify admins or others that a new member is requesting registration
This adds the entry in the admin menu.
*/
function modifyMail_menu() {
    $items = array();
  
    $items['admin/settings/modifyMail'] = array(
        'title'=>'Modify Mail Settings',
        'description' => 'Modify recipient list for new member registration notifications.',
        'page callback' => 'drupal_get_form',
        'page arguments' => array('modifyMail_admin'),
        'access arguments' => array('access administration pages'),
        'type' => MENU_NORMAL_ITEM
        );

    return $items;
}

/*
Validates the entered admin email addresses
*/
function modifyMail_admin_validate($form, &$form_state) {
    $email_list = trim($form_state['values']['modifyMail_addresses']);

    if (!is_string($email_list)) {
        form_set_error('modifyMail_admin_addresses', t('You must enter only valid email addresses separated by commas or on a new line.'));
    }

    if (!empty($email_list)) {
        //check if email was entered as comma-delimited
        $found = strpos($email_list, ",");
        $pattern = '/(\s)*/i';

        if ( is_numeric($found) && ($found != 0) ) {
            //comma-delimited
            //remove any whitespace character including [ \t\n\r\f\v]
            //drupal_set_message('modifyMail_addresses is comma-delimited');
            $email_list = preg_replace($pattern, '', $email_list);
        }
        //no comma was found, check if return-delimited
        elseif( preg_match($pattern, $email_list) == 1 ) {
            //return-delimited
            //drupal_set_message('modifyMail_addresses is return-delimited');
            //replace any whitespace character with comma
            $email_list = preg_replace('/(\s)+/i', ',', $email_list);
        }
        //drupal_set_message('email_list is:'.$email_list);


        //check again, because we just tried to normalize to comma-delimited
        $found = strpos($email_list, ",");
        //if comma-delimited (i.e. more than one email address);
        if ( is_numeric($found) && ($found != 0) ) {
            //convert email address list to array
            $aEmail = explode(",", $email_list);
          
            for($i=0;$i<count($aEmail);$i++) {
                if (!eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $aEmail[$i])){
                    form_set_error('modifyMail_addresses', 'The email address you entered in the #'.($i+1).' spot is not formatted properly or contains illegal characters.');
                }
            }
        }else{
            //contains only one email address
            if (!eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email_list)){
                form_set_error('modifyMail_addresses', 'The email address you entered is not formatted properly or contains illegal characters. Be sure to use only commas between addresses or place each address on a separate line.');
            }
        }

    }
    $form_state['values']['modifyMail_addresses'] = $email_list;
}