Using the wizard and a Validation group ?

I try to use a validation group and the wizard. Because on every page of the wizard i like to check everything bevore the user can go to the next page.
But how can i check the validation group for every page?

on page 1 i like to use page1 as group, and on page2 i like to use page2 as group.
But how can i check it? because i can't put the next button on a validation group.

So HELP :-).

This is my code, but it isn't finished..... i like to use more pages...

<asp:Wizard ID="WizardNewNieuwsbriefItem" runat="server" BackColor="#F7F6F3"
        BorderColor="#CCCCCC" BorderStyle="Solid" BorderWidth="1px"
        Font-Names="Verdana" ActiveStepIndex="1"
                onnextbuttonclick="W ...