[2008] How do I make a new instance based on a variable's type?

[Tbird761]

Hey guys. I've been programming for a long time, but there's something I've never figured out how to do in all this time. Surely there is a way to turn the following code into a sub so I don't have the same boilerplate show form code in use a thousand times in a program:

Example:

Public InstanceOfFrmGeneric As frmGeneric

If InstanceOfFrmGeneric Is Nothing Then
    InstanceOfFrmGeneric = New frmGeneric()
    InstanceOfFrmGeneric.Show()
Else
    If InstanceOfFrmGeneric.IsDisposed Then
        InstanceOfFrmGeneric = New frmGeneric()
        InstanceOfFrmGeneric.Show()
    Else
        InstanceOfFrmGeneric.Focus()
    End If
End If

Basically, I need a way to do this provided the input of the form's instance variable. Ideally something like:

Private Sub showForm(ByRef InstanceOfForm As Form)
    'Pseudo-code

    If InstanceOfForm Is Nothing Then
        InstanceOfForm = New Magic Thing Letting Me Make New Instance Of InstanceOfForm Based on Its Type Or Whatever
        InstanceOfForm.Show()
    Else
        If InstanceOfForm.IsDisposed Then
            InstanceOfForm = New New Magic Thing Letting Me Make New Instance Of InstanceOfForm Based on Its Type Or Whatever
            InstanceOfForm.Show()
        Else
            InstanceOfForm.Focus()
        End If
    End If
End Sub

Anyone know how to do this? It's probably a simple Typing thing or something, but that's not an area I'm good at since it doesn't seem to flow with the normal language.