function get_post_message($postid)
{
  // extract one post's message from the database

  if(!$postid) return '';

  $conn = db_connect();

  $query = "select message from body where postid = $postid";
  $result = mysql_query($query);
  if(mysql_numrows($result)>0)
  {
    return mysql_result($result,0,0);
  }
}