ADO code 1

Here is the code to fill the subscription length drop down box

protected void ddlMagazine_SelectedIndexChanged(object sender, EventArgs e)
{
//connection
//comand object
//DataReader

SqlConnection connect = new SqlConnection(@"Data Source=.\sqlexpress;initial catalog=MagazineSubscription;integrated security=true");

string sql = "Select SubscriptTypeName, MagDetID "
+ "From subscriptionType st "
+ "Inner Join MagazineDetail md "
+ "On st.SubscriptTypeID=md.SubscriptTypeID "
+ "Where MagID = @MagID";

SqlCommand cmd = new SqlCommand(sql, connect);
cmd.Parameters.AddWithValue("@MagID", int.Parse(ddlMagazine.SelectedValue.ToString()));

SqlDataReader reader;

connect.Open();

reader = cmd.ExecuteReader();

ddlSubscriptionLenght.DataSource = reader;
ddlSubscriptionLenght.DataTextField = "SubscriptTypeName";
ddlSubscriptionLenght.DataValueField = "MagDetID";
ddlSubscriptionLenght.DataBind();

reader.Close();
connect.Close();
}