Should Create Virtual Directory for Every Application on the server side?

Someone told me that release an asp application, by just create a sub folder under the server side default parent directory, and copy/paste all files there. Done!
It seems OK, if you just run couple of asp loose pages. But if the application contains global.asa file, It seems the variable passed in all empty -- which means the global.asa file didn't work there.
The application works fine during testing under localhost. But not after been copied to the ASP server side.
So, is it required to create a virtual directory for each application which contains it's won global.asa file?

Thanks!

If you want a global.asa file to run in a web application, you must locate the global.asa file in the root of the application virtual directory. Any other location and the global.asa file just sits there and does absolutely nothing.