Another implementation of a Drag-and-Drop mechanism between two list boxes.

Maybe it's only me, but I've searched (and found) several examples of how to implement a Drag-and-Drop mechanism in a form. These examples were generally good, some of them were even brilliant, however I found most of them hard to understand and hard to use.

Recently, I had to debug a rather ancient program where such a mechanism was used, because after a minor modification that someone else did the program stopped working as expected. This modification had nothing to do with the Drag-and-Drop functionalities that were used, but as I had to execute the code step by step, I was lead from one module to another, simply because the implementation of the D-n-D functionalities used many functions spread among different modules, with a reference to the form passed along among them (Ex. in the form: StartDrag Me, in the StartDrag function (located in another module): If IsRegistered(frmCaller) then... 'frmCaller is the reference to the form received by StartDrag and IsRegistered is another function somewhere else, etc.).

I finally decided to write a tutorial about a simple and documented system to implement Drag-and-Drop functionalities on a form and to supply a sample database to illustrate it.

Both files (the documentation and the database) can be found in the attached .zip file. The document is in pdf format and the database was created with Access 2003 (SP 3) in Access 2000 format.