passthru doesn't work with '?' after filename

[Vincent26381]

Hi,

I'm having major problems with this. Spend a whole day and night on it and can't figure it out for even a small bit:

<?
header("Content-type: application/swf");
session_start(); 


if ($var_waarde == "Gewoon een waarde"){
if ($HTTP_POST_VARS["login_user"]){

$filename = 'index2.swf'; 

passthru( "cat " . $filename );
}
}
?>

That works, and this doesnt:

<?
header("Content-type: application/swf");
session_start(); 


if ($var_waarde == "Gewoon een waarde"){
if ($HTTP_POST_VARS["login_user"]){

$filename = 'index2.swf?login_user=' . $login_user; 

passthru( "cat " . $filename );
}
}
?>

When I use the last script I simply get a 'movie not loaded'. At least it should load the movie, maybe not passing the var, but no movie at all?!
I have no idea why this shouldn't work; all I want to do is pass the var to flash.

Thank you,

Vincent