Need help adding a data input form

system5

I'm currently trying to add a data input form to a login system.

However currently my code won't let me input anything, but just logs me out instead. I have a sign up page that works perfectly, but adding another page for data input has been tricky. Any help would be appreciated.

The page that causing me issues....

<?
include("include/activity.php");
?>
<?
/**
 * If user is not logged in, then do not display anything.
 * If the user is logged in they cab book
 * account information, with the current email address
 * already in the field.
 */
if($session->logged_in){
if(isset($_SESSION['bookingSuccess'])){
   /* Registration was successful */
   if($_SESSION['bookingSuccess']){
      echo "<h1>Booked</h1>";
      echo "<p>Thanks!".$_SESSION['bookingName']."</b>, your booking is now part of the system! "
          ."Click here <a href=\"main.php\">to go back</a>.</p>";
   }
   /* Registration failed */
   else{
      echo "<h1>Failed to Book</h1>";
      echo "<p>Theres been a error for that roomname<b>".$_SESSION['bookingName']."</b>, "
          ."could not be completed.<br>Please try again at a later time.</p>";
   }
   unset($_SESSION['bookingSuccess']);
   unset($_SESSION['bookingName']);
}
?>
<html>
<title>Room Booking</title>
<body>
<?
if($form->num_errors > 0){
   echo "<td><font size=\"2\" color=\"#ff0000\">".$form->num_errors." error(s) found</font></td>";
}
?>
<h1>Room Booking in name of: <? echo $session->username; ?></h1>
<form action="process.php" method="POST">
Room Name : <input type="text" name="roomname" maxlength="10" value="<? echo $form->value("roomName"); ?>"></td><td><? echo $form->error("roomName"); ?>
<input name="send" type="submit" value="Submit">
<tr><td colspan="2" align="left"><a href="main.php">Back to Main</a></td></tr>
</table>
</form>

<?
}

?>
</body>
</html>

Taken from my sql php page:

  function bookingAdd($roomname){
      $q = "INSERT INTO ".tb_booking." VALUES ('$roomname')";
      return mysql_query($q, $this->connection);
   }

The function from activity.php that relates to this page.

function booking($roomname){
      global $database, $form, $mailer;  //The database, form and mailer object

  /* Username error checking */
  $field = "roomName";  //Use field name for roomname
  if(!$roomname || strlen($roomName = trim($roomName)) == 0){
     $form->setError($field, "* Roomname not entered");
  }
  else{
     /* Spruce up username, check length */
     $subuser = stripslashes($subuser);
     if(strlen($subuser) < 2){
        $form->setError($field, "* Roomname below 2 characters");
     }
     else if(strlen($subuser) > 10){
        $form->setError($field, "* Roomname above 30 characters");
     }

  }
  }

and finally the function related to process.php

function procBooking(){
      global $session, $form;
      /* Convert username to all lowercase (by option) */
      if(ALL_LOWERCASE){
         $_POST['roomName'] = strtolower($_POST['roomName']);
      }
      /* Registration attempt */
      $retval = $session->booking($_POST['roomName']);

  /* Registration Successful */
  if($retval == 0){
     $_SESSION['bookingName'] = $_POST['user'];
     $_SESSION['bookingSuccess'] = true;
     header("Location: ".$session->referrer);
  }
  /* Error found with form */
  else if($retval == 1){
     $_SESSION['value_array'] = $_POST;
     $_SESSION['error_array'] = $form->getErrorArray();
     header("Location: ".$session->referrer);
  }
  /* Registration attempt failed */
  else if($retval == 2){
     $_SESSION['bookingName'] = $_POST['roomName'];
     $_SESSION['bookingSuccess'] = false;
     header("Location: ".$session->referrer);
  }
   }