problem with starting a session

hi, i have a problem with starting a session in the page that validates the user input and sends it tothe database, when the user clicks register he gets this error Warning: session_start(): Cannot send session cookie - headers already sent by (output started at c:\inetpub\wwwroot\ads4u\data_valid_fns.php:25) in c:\inetpub\wwwroot\ads4u\register_new.php on line 89 Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at c:\inetpub\wwwroot\ads4u\data_valid_fns.php:25) in c:\inetpub\wwwroot\ads4u\register_new.php on line 89 and here is the code i wrote : <?

    $email=$HTTP_POST_VARS['email'];
    $passwd=$HTTP_POST_VARS['passwd'];
    $passwd2=$HTTP_POST_VARS['passwd2'];
    $title=$HTTP_POST_VARS['title'];
    $name1=$HTTP_POST_VARS['name1'];
    $name2=$HTTP_POST_VARS['name2'];
    $phone=$HTTP_POST_VARS['phone'];
    $mobile=$HTTP_POST_VARS['mobile'];
    $address1=$HTTP_POST_VARS['address1'];
    $address2=$HTTP_POST_VARS['address2'];
    $town=$HTTP_POST_VARS['town'];
    $pb=$HTTP_POST_VARS['pb'];
    $country=$HTTP_POST_VARS['country'];
    $occupation=$HTTP_POST_VARS['occupation'];

session_start(); if (!filled_out($HTTP_POST_VARS)){ echo "You Haven't filled your registeration details correctly, Please go back and try again"; exit; } if (!valid_email($email)){ echo "That is not a valid email address. Please go back and try again."; exit; } if ($passwd != $passwd2){ echo "The passwords you entered do not match - please go back and try again."; exit; } if (strlen($passwd)<6 || strlen($passwd) >16){ echo "Your password must be between 6 and 16 characters Please go back and try again."; exit; } can anyone tell me please where is the problem and how to solve it, i test those scripts on my local server IIS, i use windows XP and last version of PHP and MYSQL, thanks _________________________________________________________________ MSN 8 with e-mail virus protection service: 2 months FREE* http://join.msn.com/?page=features/virus