How can I split a one section of a grid into another window?

Hello everyone,

I am rather new to VB.NET and I am currently working through a book I bought in order to start learning a little bit about this language, however, i've come up against some design issues.

Basically, I was wondering whether it would be possible to split the login section of the 'MainWindow.xaml.vb' up into another separate window, and if so, how I can go about doing this?

I've attached a .zip of the code should anyone be kind enough to take a look at it for me (apologies for including the bin and obj folders but removing them seems to create errors)

I'll not hide the fact that this has been copied from the book with a few minor...(being the operative word) changes made.

Thanks for any help in advance!