I assume you can open any htm file on your desktop Web directory from your phone, eg.

http://nnn.nnn.nnn.nnn/images/imageHelp.htm

where nnn.nnn.nnn.nnn is your server's external IP address.

Your router must redirect port 1433 to the host machine, and your firewall must not prevent that (you might turn it off temporarily).

Also, check that you can run any asp file on your server from your phone.

If not, try running the app directly on your server using its own internal IP address.

I don't know how you called the images.asp page, but increasing the help level to 2 or 3 might help diagnose the problem:

http://nnn.nnn.nnn.nnn/images/images.asp?helplevel=2

You might try adding a response.write(driverHost) statement on the program's driverHost variable to see what it looks like (while disabling the actual connection: connectionHost.Open driverHost).

That variable is set as:

driverHost = "DRIVER={SQL Server};SERVER=" & hostServer & ";UID=" & hostLogin & ";PWD=" & hostPassword & ";DATABASE=" & hostDatabase

The other place where connectivity might be an issue is where you can get the opening page, but you can't retrieve a file that's listed (which resides in the SQL database). For simply viewing a file, go to the image.asp file (not images.asp) and put in the same sort of diagnostics.

These are the places where things generally fail, and it usually has something to do with simply connecting to the server (the app itself is fairly trivial).

Basically, if you can connect to your SQL Server from your phone's Web browser using direct calls that by-pass the app, the app should work OK.