WPF and WinForms

I want to make my next application in WPF but am worried as part of design process has found I will need about 6 forms.

On button click display another one.

Also could DockPanel work the same way as a panel does in WinForms?
using viability or bring to front change what a user is working on?

ok I can open this

vb Code:

Dim newWindow As New Window1
newWindow.Show()

but how can I do this i don't keep opening a new window each time i.e i don't want 5 windows open??