Sorry: Found a copy of "global.inc.php" over-wrote the blank and ..well got the admin page back.

Hi.. reveived the security email, downloaded the files and copied the Over the existing on the server and now when I click the store link I get a 404 Error.
When I click my store admin link I get "My SQL ERROR 1046: No Database Selected"..
Question is: How do I get it back, i.e. restore the link?
(really simple instuctions, they don't let me play w/ power tools or sharp objects!)

jim