[PHP] header problems

[Brent Clark]

Hi All

I need to display a javascript window with some text displayed in to.
After the execution and displaying of this windows, I have two executable php script 
that perform some task for me.
After all this I need the page to direct to another page.

I keep getting this header error.

If someone know of a solution, that would be most appreciated

Here is my code:
if($read){
        require_once('lib/functions.inc');
                                            {execute the javascript window here}
        exec("/var/www/html/ag.php");
        exec("/var/www/html/convert_tif2pdf.php");
        header("Location: capture.php");
        exit;
        }

Kind Regards and thank you
Brent Clark