custom login

[sadam]

I require a modification to the login system so that it can accept username and password from the address bar e.g.

http://mysite.com/forum/customlogin.php?user=name&pass=word

I understand the security elements

I just need to make sure the user and pass are correct and to display a message like echo "valid";
and if they are not valid then another message echo "not valid";

All this need to be run in this php file with no redirects

If anyone needs anymore information just let me know

Thanks in advance to anyone that helps