protected void Page_Load(object sender, EventArgs e)
 {
     //if session of user is null
     if (Session["user"] == null)
     {
         //if session of admin is not null
         if (Session["admin"] != null)
         {
             //list the gridview from database
             List <Member> members = ParticipantMgr.getAllParticipant();
             gvMember.DataSource = members;
             gvMember.DataBind();
         }
         else
         {
             //redirect to the invalid page
             Response.Redirect("InvalidPage.aspx");
         }
     }
     else
     {
         //redirect to the invalid page
         Response.Redirect("InvalidPage.aspx");
     }
 }
    protected void gvMember_SelectedIndexChanged(object sender, EventArgs e)
    {
        Panel1.Visible = true;
        List <Member>       members       = ParticipantMgr.getAllParticipant();
        Member              m             = members[gvMember.SelectedIndex];
        List <ShoppingCart> shoppingcarts = ShoppingCartDBMgr.getAllShoppingCartByAdmin(m.Email);

        gvShoppingCart.DataSource = shoppingcarts;
        gvShoppingCart.DataBind();
    }