Combining Projects using VS 2010

[rhavis]

I needed to select an index from a list for a GUI project (VB .NET), so I created a new project in VB 2010 to load a list box from a text file and retrive the index of a record. I use a form load subroutine to load the list box and ListBox1_SelectIndexChanged to get the index. This works perfectly as a stand alone project. I added the list box projet to the GUI project in VS 2010: File > Add Project > Existing Project and passed variables, using a Global Variable Class, from the GUI public subroutine to the list box public subroutine, and this works well. The subroutines are in different classes. When I call the list box subroutine from the GUI to load the list box, the text is processed and processing returns but the list box does not open as it did in the stand alone list box project. Any ideas for trouble shooting this problem? Thanks