Retrieve database information dynamically into label using DropDownList

I'm trying to retrieve data into labels dynamically. Meaning to say the label will change as i change the DropDownList selected item. Is it possible?

aspx:

<asp:DropDownList ID="ddl_CNo" AutoPostBack="true" runat="server" Height="16px" Width="138px" OnSelectedIndexChanged="ddl_CNo_SelectedIndexChanged" >
                </asp:DropDownList>

aspx.cs:

//page load box retrieve
    SqlCoection myCoect2 = new SqlCoection(_coStr);
    string strCommandText2 = "SELECT Card_Type, Card_Type2, Card_Number, Card_Number2, Name_On_Card, Name_On_Card2, Expired_Date, Expired_Date2 From Card_Details where Card_Id = @Card_Id";
    myCoect2.Open();
    SqlCommand cmd2 = new SqlCommand(strCommandText2, myCoect2);
    cmd2.Parameters.AddWithValue("@Card_Id", 1);

    ////open coection and retrieve data by calling ExecuteReader

    SqlDataReader dr2 = cmd2.ExecuteReader();

    if (dr2.Read())
    {

        string CNo1 = dr2["Card_Number"].ToString();
        string CNo2 = dr2["Card_Number2"].ToString();

        CNo = new List<string>();
        CNo.Add(dr2["Card_Number"].ToString());
        CNo.Add(dr2["Card_Number2"].ToString());

        ddl_CNo.DataSource = CNo;
        ddl_CNo.DataBind();

  ddl_CNo.Text = dr2["Card_Number"].ToString();
  ddl_CNo.Text = dr2["Card_Number2"].ToString();
  Lbl_CardName.Text = dr2["Name_On_Card"].ToString();
  Lbl_CardName.Text = dr2["Name_On_Card2"].ToString();
  Lbl_CardType.Text = dr2["Card_Type"].ToString();
  Lbl_CardType.Text = dr2["Card_Type2"].ToString();
  Lbl_EDate.Text = dr2["Expired_Date"].ToString();
  Lbl_EDate.Text = dr2["Expired_Date2"].ToString();


    }
    dr2.Dispose();
    dr2.Close();

    myCoect2.Close();

    if (!IsPostBack)
    {

        LoadCart();

    }
}

DDLSelectedIndexChanged:

 protected void ddl_CNo_SelectedIndexChanged(object sender, EventArgs e)
{
    {
        SqlCoection myCoect2 = new SqlCoection(_coStr);
        string strCommandText2 = "SELECT Card_Type, Card_Type2, Card_Number, Card_Number2, Name_On_Card, Name_On_Card2, Expired_Date, Expired_Date2 From Card_Details where Card_Id = @Card_Id";
        myCoect2.Open();
        SqlCommand cmd2 = new SqlCommand(strCommandText2, myCoect2);
        cmd2.Parameters.AddWithValue("@Card_Id", 1);
        SqlDataReader dr2 = cmd2.ExecuteReader();

        if (dr2.Read())
        {

            string CNo1 = dr2["Card_Number"].ToString();
            string CNo2 = dr2["Card_Number2"].ToString();

            CNo = new List<string>();
            CNo.Add(dr2["Card_Number"].ToString());
            CNo.Add(dr2["Card_Number2"].ToString());

            ddl_CNo.DataSource = CNo;
            ddl_CNo.DataBind();

            if (ddl_CNo.SelectedItem.Equals("Card_Number"))
            {
                Lbl_CardName.Text = dr2["Name_On_Card"].ToString();
                Lbl_CardType.Text = dr2["Card_Type"].ToString();
                Lbl_EDate.Text = dr2["Expired_Date"].ToString();
            }
            else if (ddl_CNo.SelectedItem.Equals("Card_Number2"))
            {
                Lbl_CardName.Text = dr2["Name_On_Card2"].ToString();
               Lbl_CardType.Text = dr2["Card_Type2"].ToString();
               Lbl_EDate.Text = dr2["Expired_Date2"].ToString();
            }
            dr2.Dispose();
            dr2.Close();

            myCoect2.Close();
        }
    }
}

picture for reference:

I'm really new to all these, any help is greatly appreciated :)