Need to reference text box value within an argument

I load a lot of refurbished computers and I am (trying to) create a program to help me activate all of them. They all have their own genuine Product Keys. I would like to use SLMGR.VBS to activate through a button. I already have. 

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Process.Start("slmgr.vbs", "/ipk 88888-88888-88888-88888-88888")

    End Sub

Is it possible to exchange "88888-88888-88888-88888-88888" and make it reference "TextBox1.Text" . This way I can enter the key on the screen and have it activate at the press of a button. 

I am also planning to add this in after.

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Process.Start("slmgr.vbs", "/ato")

    End Sub

If there is a way I would be very appreciative, if not, is there another way I could write it to do the same thing?

-John