Saving An Attachment File

I have a basic classified as form where people can enter their name, title, message, and include an attachment. I have it working so that it will save the name, title, and message into my database. However, I don't know the code for the attachment.

What I'd like to have happen is this:

When they click save, the path name that was entered is saved as the Internal_Name and the actual attachment itself is placed into a file called ClassFiles. They are connected through the use of a class_ID number.