Problems With Chttpsession After Deploying To Server

I made an application that is storing two values via CHttpSession. It is working perfectly on my development platform, but after deploying to my provider, the values are not being stored, and the application is not working properly. Anybody can give me a clue what could be the problem?

Here the code to store the parameters:

	$session=new CHttpSession;


	$session->add('Flt_Local', $_GET['Local']);

	$session->add('Flt_Cancel', $_GET['Cancel']);

and here to retrieve them:

public function defaultScope()


    $session=new CHttpSession;

    return array(

        'condition'=>"Cancel='".$session['Flt_Cancel']."' AND Local='".$session['Flt_Local']."'",