I can echo the id number of a member. "The ID Number is 239." I am now trying to enter number of the user as the organiserid.

I can insert eventname into the table but I am struggling to add the id number. Can anyone advise how I should be doing this please.

      <div class="boardintro">
The ID Number is <?php echo (!empty($row['id'])) ? $row['id'] : ''; ?>

                $organiserid = trim($_POST['$id']); 
        $eventname = mysql_real_escape_string(trim($_POST['eventname']));
                $query = mysql_query("INSERT INTO table (eventname, organiserid) VALUES ('" .$eventname."', '" .$organiserid."')");
                if($query) {
                } else {
  $error = "There was a problem with the submission. Please try again.";