Simple; dataflex web service...
Just use the wizards for a webapp (clean up later).
And the wizard for a web service.
Create a function ’myuppercase’ to start with and in the code explorer right click to make it published.
Compile and run and you see a test page created.

See the url is tempuri or something like that. In the properties panel of the web service set a better service name. Compile/ run and see the better url.

From there I suggest you put all logic in a class package. Within the published function create the object, call it and destroy it.
That way you do not have to worry about hanging properties.
Also it makes it easier for unit testing if you decide to build that and / or a windows frontend for testing.

But overall you’ll find it is much easier than you might expect.

Cheers from OZ
Marco