<?php
function dataValidation($request) {
   global $school_num;

   extract($request,EXTR_PREFIX_ALL,"P");
   $error_message = "";

   // Check if the user id is provided
   if (strlen($P_userid) == 0) {
      $error_message = getLanguageText('ERRORMSG-USER-ID-REQUIRED') . " - $P_userid";
      return($error_message);
   }

   // Check for an invalid user id
   if ($P_userid != db_escape_string($P_userid)) {
      $error_message = getLanguageText('ERRORMSG-RESTRICTED-USER-ID');
      return($error_message);
   }

   if (strpos($userid,' ') !== false) {
      $error_message = getLanguageText('ERRORMSG-INVALID-USER-ID');
      return($error_message);
   }

   if ($userid == 'superuser' || $userid == 'admin') {
      $error_message = getLanguageText('ERRORMSG-RESTRICTED-USER-ID');
      return($error_message);
   }

   // Check if the user id is already in use
   $userid = db_escape_string($P_userid);
   $query = "select * from users " .
            "where school_num = $school_num " .
            "and userid = '" . db_escape_string($userid) . "'";
   $results = db_query($query);
   if (db_num_rows($results) > 0) {
      $error_message = getLanguageText('ERRORMSG-USER-ID-NOT-AVAILABLE');
      return($error_message);
   }

   // Check for missing fields
   $requiredFields = array('password','type','status');
   for ($i = 0; $i < count($requiredFields); $i++) {
      $field = $requiredFields[$i];
      if (strlen($request[$field]) == 0) {
         $error_message = getLanguageText('ERRORMSG-MISSING-DATA');
         return($error_message);
      }
   }

   return(0);
}
?>