How to return to main page after transaction is done.

I currently developed a website using asp that involved with credit
card transaction.the 3rd party is using php.from my page to the 3rd
party it seems to be ok. the problem now is after the transaction is
done, i need to return back to my page which is credit.asp

the 3rd party provide the return url input box for me to insert in it:
http://www.anaedar.com/credit.asp?status=$status;

i'm not quite familiar with php..is the way i insert it correct?

the page seems like it doesn't read the status($status;) that i pass.
Is there anybody can show me how to make the $status valid and run
perfectly??
Thank u..

Regards,
-Berry-