Can't change "next" button text in wizard control

I have a wizard control with three steps..Start, Step and finish.

I would like to change the text in the "Next" button, but setting btnNext.tex="whatever" does not seem to work. I am able to change the "Enabled" property of the button, so I am pretty sure my button reference is correct. I get a reference to the button using..

Dim btnNext as Button

Sub Page_Init()

 btnNext= myWizard.FindControl("StartNavigationTemplateContainerID").FindControl("StartNextButton")

End Sub

Sub Page_Load()

 btnNext.Text="Custom Text" ' this does not work.

 btnNext.Enabl ...