Selecting the tab in sitecore
===

I am using Sitecore and I have a webpage which contains a tab. This tab can have 1 or many children. Now there is a promotions control which dynamically change as according to which tab is selected. 

So if I selected Tab1, then some promotion will be shown at that page. Tab2 might have different/same promo. These two are placed in different controls. 

All I got is this code so far:

            Sitecore.Data.Database db = Sitecore.Context.Database;
            Item home = db.GetItem(Sitecore.Context.Site.StartPath);
            var getItems = (from Item item in currItem.Children.InnerChildren 
                            select item).ToList();

Result of this query is 3 items. Because there are 3 tabs. These tabs are in repeater like this:

    <asp:Repeater ID="rptPromo" runat="server" OnItemDataBound="rptPromo_ItemBound">
    <ItemTemplate>
        <table width="100%">
              <tbody>
                     <tr>
                        
                         <td>
                             <h2><sup><sc:Text ID="txtPromo" Field="PromoText" runat="server" /></sup></h2>
				        </td>
                        
                     </tr>

               </tbody>
        </table>    
    </ItemTemplate>
    
</asp:Repeater>

How to get the info of which tab is selected. I am changing the PROMO control in a separate function:

     protected void rptPromo_ItemBound (Object sender, RepeaterItemEventArgs e)
        {
            
            Item i = e.Item.DataItem as Item;
            Text txtPromo = e.Item.FindControl("txtPromo") as Text;
            //txtPromo.Attributes.Add("txtPromo", txtPromo);
            //HTMLControl hyperLinkLookUp = e.Item.FindControl("") as 
            string s;
        }

What should I do?