Can anybody help?

I am creating a Vb.Net "AddIn" for SolidWorks.

Does anybody know how to get the "Document Type" using a Sub-Routine?

The reason why I need to find the document type using a sub-routine is the fact that I have created various custom buttons that perform various duties and they all require the document type and I do not want to have several copies of the same code.

By document type, I mean