Changing the DataField of a DataGrid at runtime

Hey all,

It's been a while since I did any programming in VB/ASP.NET so don't shoot me if this is obvious.

I have a datagrid control on a page that I populate when the page is loaded. I'm changing the functionality of the page so that based on a certain variable the DataGrid will display different parts of the data (i.e. depending on which user is viewing the data).

I currently deffine the Datagrid in the aspx file as follows:
<TD colSpan="2"><asp:datagrid id="dgdContactsList" runat="server" BorderWidth="1px" BorderColor="#CCCCCC" AllowPaging="True"
            DataKeyField="tContact_id" AutoGenerateColumns="False" PageSize="15">
            <Columns>
                  <asp:TemplateColumn>
                        <ItemTemplate>
                              <asp:ImageButton id="Imagebutton1" runat="server" CommandName="ViewContact" CausesValidation="false"
                                    ToolTip="Click to view the contact." ImageUrl="BAS/gui/view.gif"></asp:ImageButton>
                        </ItemTemplate>
                  </asp:TemplateColumn>
                  <asp:BoundColumn DataField="tContact_Fname" SortExpression="tContact_Fname" HeaderText="First Name"></asp:BoundColumn>
                  <asp:BoundColumn DataField="tContact_Lname" SortExpression="tContact_Lname" HeaderText="Last Name"></asp:BoundColumn>
                  <asp:BoundColumn DataField="tContact_OfficeTel" SortExpression="tContact_OfficeTel" HeaderText="Office Tel."></asp:BoundColumn>
                  <asp:BoundColumn DataField="tContact_MobileTel" SortExpression="tContact_MobileTel" HeaderText="Mobile"></asp:BoundColumn>
                  <asp:BoundColumn DataField="tContact_EMail" SortExpression="tContact_EMail" HeaderText="EMail"></asp:BoundColumn>
                  <asp:TemplateColumn Visible="False">
                        <ItemTemplate>
                              <!--<asp:LinkButton runat="server" Text="Edit" CommandName="" CausesValidation="false"></asp:LinkButton>-->
                              <asp:ImageButton id="Imagebutton2" runat="server" CommandName="EditContact" CausesValidation="false"
                                    ToolTip="Click to edit the contact." ImageUrl="BAS/gui/edit.gif"></asp:ImageButton>
                        </ItemTemplate>
                  </asp:TemplateColumn>
                  <asp:TemplateColumn Visible="False">
                        <ItemTemplate>
                              <!--<asp:LinkButton runat="server" Text="Del" CommandName="" CausesValidation="false"></asp:LinkButton>-->
                              <asp:ImageButton id="btn_deletecontact" runat="server" CommandName="DeleteContact" CausesValidation="false"
                                    ToolTip="Click to delete the contact." ImageUrl="BAS/gui/delete.gif"></asp:ImageButton>
                        </ItemTemplate>
                  </asp:TemplateColumn>
            </Columns>


So, what i need to do now is write a function that would allow me to change the values of the datafield for the boundcolumns onload of the page. I guess I don't mind creating the boundcolumns as part of that function rather than predefining them in the aspx.

Suggestions?