[Mono-list] ASP.NET object troubles

[Raul Carolus]

Greetings all.

I have a aspx, with codebehind, that i'm trying to get tabcontrol-like 
behavior on.  I have everything working, except for the visual effects 
to determine what tab is selected.

I'm using buttons as the tabs, and setting their CssClass to indicate 
whether the button is selected or not.  I use a Session variable to 
store what button is selected.

However, when the page loads or does a postback,  I'm always getting 
null references when working with the buttons.

Here's some of my code:

public class StudentsPage : Page
     {
     	private long studId;
     	protected System.Web.UI.WebControls.Button InfoButton, BeltButton, 
InstButton, CertsButton, TrnyButton, BioButton;
     	protected Button selectedButton;


         private void Page_Load(Object Sender, System.EventArgs e)
         {
         	Console.Write("Page_Load\n");
         	
         	if(IsPostBack)
         	{
         	Console.Write("Postback\n");
         	}
         	InfoButton.CssClass="Button";
         	BeltButton.CssClass="Button";
         	InstButton.CssClass="Button";
         	CertsButton.CssClass="Button";
         	TrnyButton.CssClass="Button";
         	BioButton.CssClass="Button";
         	
         	if((string)Session["student_tab"] == "info")
         		InfoButton.CssClass="SelectedButton";

If I comment out the code referening the buttons, everything else works 
fine.

I've tried putting the code in various procedures, OnInit, OnPreRender, 
etc, all with the same results.

Is there something I'm doing wrong?  I've worked for four days on this 
and am at my wits end.  Can someone lend a hand?

Thanks,

Raul