Often we write applications which must upload files, then get back success indicators or other data from
the server.

There are several ways to accomplish that, but the easiest is using THTMLForm's with TFileComboBox and the user selects the file.

I wrote a blog entry that explores some issues around that sort of activity.

See: https://erickengelke.com/h/posts/post17/
EWB Programming Books and Nice Component Library
See my EWB BLOG posts, at:
http://www.erickengelke.com