public function saveImage() {
            // This little part checks if user is logged in and alse gets us an user interface object to work with later.
              $user = new User();
              $ui = $this->get('ui');
            if (!is_object($ui) || $ui->getUserID() < 1) {
               return false;
            }
 
            // That's where we start working with files.
            // First, check that filetype is gif, jpg or png (to know that we're getting an image). And check if it's not too big (less than 20000 bytes)
              if (($_FILES["file"]["type"] == "image/gif") || ($_FILES["file"]["type"] == "image/jpeg")
                      || ($_FILES["file"]["type"] == "image/pjpeg") || ($_FILES["file"]["type"] == "image/png")
                      && ($_FILES["file"]["size"] < 20000)) {
                  // if theres an error -- drop a message and quit.
                  if ($_FILES["file"]["error"] > 0) {
                      $this->set("error", "There was an error uploading the image. Try again or tell the admin, he'll fix it.");
                  }
                  else {
                     // If there were no errors and image is fine, let's move it.
                     // Create a temporary file (we only need name so I unlink it afterwards)
                      $tmp_name = tempnam(DIR_TMP, "tmp_avatar");
                      unlink($tmp_name);
 
                  // I want to attach an extension to the file (since there is none when temporary file is created by php)
                  // So I strip type of "image/" bit and attach the rest to the filename.
                      $tmp_name = $tmp_name.".".preg_replace("/image\//", "", $_FILES["file"]["type"]);
 
                  // Then I move the uploaded file to the proper location with extension attached (to concrete's /file/tmp/tmp_avatar<whatever unique stuff here>.extension
                      move_uploaded_file($_FILES["file"]["tmp_name"], $tmp_name);
 
                      // And convert it!
                      // The line is "convert -resize 80x80> one_file.png another_file.jpg" where "80x80>" means to 80x80 px if image is bigger than that. 
                      // The resulting file is /files/avatars/1.jpg (where 1 is user id).
                      $convert_result = shell_exec('convert -resize '.AVATAR_WIDTH.'x'.AVATAR_HEIGHT.'> '.$tmp_name.' '.DIR_FILES_AVATARS.'/'.$user->getUserID().'.jpg 2>&1');
 
                      // If there was an error -- show it to the user. Otherwise, update DB -- concrete should know user now has avatar.
                      if ($convert_result) {
                          $this->set("error", "Couldn't resize your image, try again.");
                      }
                  else {
                         $data['uHasAvatar'] = 1;
                     $ui->update($data);
                  }
                  }
              }
              else {
                  $this->set("error", "I only accept .jpg, .gif or .png files as images.");
              }
          }