Modless Messagebox in solidworks addin

Hi there!

I am writting a solidworks addin. The addin is doing something an then it should show the user a Messagebox or a Form that tells the user do to something now in solidworks.

When the user finished doing his work he should press the "Go on..." or something like "Ok" on the Messagebox and the programm should continue. If you have a stand alone exe this will work setting the Form to a non Modal form, but when it is an addin the form or messagebox is showen but the user has no control within solidworks.

Has somebody a solution for me?

SolidworksApi macros