gzip and firefox problem

[fascom746]

Hello;

I have enabled gzip for my site by using
<?php
ob_start("ob_gzhandler");
{my page Code}
ob_flush();
?>

I works perfectly with internet explorer but when I open my site with firefox it shows a blank page. Is there any method to enable gzip for fire fox ? And Could I use
gzip with internet explorer only by detecting the user agent while showing
firefox users non-gzip page?

Thanks