Exchange 2003 OWA

I recently upgraded from Exchange 5.5 to Exchange 2003 and everything is running great. I just have a question on the OWA. When I was on 5.5 when I went to OWA it asked for the mailbox name and I put that in and hit enter and then it prompted me for the username and password. Using this method I was able to put in the username in the first prompt and then put the Exchange Services username and password in the second prompt and it would allow me in to any users mailbox. This was extremely useful in troubleshooting user email issues. With Exchange 2003 OWA it doesn’t give me those choices. There isn’t a default web page when you connect, it just asks for the username and password to access the mailbox. Is there a way to get around this in 2003 OWA. Thanks in advance.