Session not working

[Wstar]

I'm having trouble testing my session handler.  The following is my session handler code:

[code]
<?php
$SESS_DBHOST = ""; /* database server hostname */
$SESS_DBNAME = ""; /* database name */
$SESS_DBUSER = ""; /* database user */
$SESS_DBPASS = ""; /* database password */

$SESS_DBH = "";
$SESS_LIFE = get_cfg_var("session.gc_maxlifetime");

function sess_open($save_path, $session_name) {
global $SESS_DBHOST, $SESS_DBNAME, $SESS_DBUSER, $SESS_DBPASS, $SESS_DBH;

if (! $SESS_DBH = mysql_pconnect($SESS_DBHOST, $SESS_DBUSER, $SESS_DBPASS)) {
echo "<li>Can't connect to $SESS_DBHOST as $SESS_DBUSER";
echo "<li>MySQL Error: ", mysql_error();
die;
}

if (! mysql_select_db($SESS_DBNAME, $SESS_DBH)) {
echo "<li>Unable to select database $SESS_DBNAME";
die;
}

return true;
}

function sess_close() {
return true;
}

function sess_read($key) {
global $SESS_DBH, $SESS_LIFE;

$qry = "SELECT value FROM sessions WHERE sesskey = '$key' AND expiry > " . time();
$qid = mysql_query($qry, $SESS_DBH);

if (list($value) = mysql_fetch_row($qid)) {
return $value;
}

return false;
}

function sess_write($key, $val) {
global $SESS_DBH, $SESS_LIFE;

$expiry = time() + $SESS_LIFE;
$value = addslashes($val);

$qry = "INSERT INTO sessions VALUES ('$key', $expiry, '$value')";
$qid = mysql_query($qry, $SESS_DBH);

if (! $qid) {
$qry = "UPDATE sessions SET expiry = $expiry, value = '$value' WHERE sesskey = '$key' AND expiry > " . time();
$qid = mysql_query($qry, $SESS_DBH);
}

return $qid;
}

function sess_destroy($key) {
global $SESS_DBH;

$qry = "DELETE FROM sessions WHERE sesskey = '$key'";
$qid = mysql_query($qry, $SESS_DBH);

return $qid;
}

function sess_gc($maxlifetime) {
global $SESS_DBH;

$qry = "DELETE FROM sessions WHERE expiry < " . time();
$qid = mysql_query($qry, $SESS_DBH);

return mysql_affected_rows($SESS_DBH);
}

session_set_save_handler(
"sess_open",
"sess_close",
"sess_read",
"sess_write",
"sess_destroy",
"sess_gc");
?>[/code]

In my index.php file i have the following:

[code]
include("session_mysql.php");
session_start();
[/code]

now, I've tested the session here;
with the code '$_SESSION['user']="blue";'
and it works.

But here is my problem.  index.php calls another file, navigation.php.  Within navigation, I want to put the username in $_SESSION['user'].  This is what i can NOT fix.  The following code is my navigation.php file.  The session value 'blue' works, but the session value 'red' does not?!  Why doesn't 'red' get put in the session value?

Note:  - The red and blue code is not in there at the same time. 
          - The case 'submit' has more to it but i can not show here.
        - When I load my site, then hit the submit button the session value is BLUE not RED?!!
        -  I also know the case submit is running becuase it echos 'submit'
[code]
<?php
        switch($action){
          case "nothing":
     
      ?>
     
            <td align="left" width="100">
              Please Login!
            </td>
            <td align="right">
              <form method="post">
                <input type=""text" name="nav_username" size="7" maxlength="15" value="" />
                <input type=""text" name="nav_password" size="7" maxlength="15" value="" />
                <input type="submit" name="submit_login" value="Login" />
              </form>
            </td>
      <?php
          $_SESSION['user']="blue";
          break;
      case "submit":
        $_SESSION['user']="red";
        echo "submit";
        break;
}
[/code]

When i try to insert a value in the session within the submit case it does NOT work.  yet, when its outside of the case it does?