Calling DB subroutine using HTTP RESTfull framework

I am attempting to build a application that will use the RESTfull HTTP framework to make subroutine calls to retrieve data that has been derived / calculated from a fairly large and complex database application containing over 800 tables. What I want to do is conceptually simple: call a subroutine with 5 parameters all of which can be input or output. all of the input / outputs are JSON strings. I have attempted to build a simple test application that has one input “ID” and expects a single return item as a JSON string. Here is what I have so far.

Dim vx As New HTTPSocket
Dim request as New Dictionary
request.Value(“ID”) = “2”

I can’t get it to execute and I don’t know how to retrieve the return data. Can anyone help, or have a code example that completes a RESTfull call to a subroutine?