$_SESSION issues

[Michael Morris]

Have some problems with the following code.

PHP Code:

if ($dialogmessage)
{
    if (($vbulletin->session->vars['dialog_display_time'] + 1200) < TIMENOW)
    {
        $dialogid = 'greeting';
        eval('$dialogs .= "' . fetch_template('dialog') . '";');
        $dialoglauncher = "dialogLaunch('dialog_$dialogid');";
        $vbulletin->session->vars['dialog_display_time'] = TIMENOW;
    }
    else if ($vbulletin->options['sysannounce_global'] && (($vbulletin->session->vars['dialog_global_display_time'] + 1200) < TIMENOW))
    {
        $dialogid = 'greeting';
        eval('$dialogs .= "' . fetch_template('dialog') . '";');
        $dialoglauncher = "dialogLaunch('dialog_$dialogid');";
        $vbulletin->session->vars['dialog_global_display_time'] = TIMENOW;  
    }
} 


I tried writing directly to $_SESSION but vbulletin apparently erases the contents of that var as a security precaution. I tried using

$vbulletin->session->vars['session_url']['dialog_global_display_time']

and that screwed things up. I'm at a loss here, I don't want to store this information on the user table but it's starting to look like I might have to for lack of a better way to carry this over

(For those wondering, the code launches an interstatial pop-up at session start with forum announcements or private messages. I don't want that interstatial launching once it's been seen. I'd like once per browser session but I'll settle for once per hour. The code is broken down slightly because I have a global announcement I use to warn users that I'm about to shut the boards down).