protected void Page_Load(object sender, EventArgs e)
    {
        //This code is filling in the Dropdownlist with data from Category table
        string strCategory = "sdp_ViewCategory";
        DataSet dsCategory = new DataSet();
        SqlDataAdapter daCategory = new SqlDataAdapter (strCategory, conn);
        daCategory.Fill(dsCategory, "Categories");
        ddlItems.DataSource = dsCategory;
        ddlItems.DataMember = "Categories";
        ddlItems.DataTextField = "Description";
       // ddlItems.DataSourceID = "CategoryID";
        ddlItems.DataBind();
        ddlItems.Items.Insert(0, "Please select a category");
    }

protected void ddlItems_SelectedIndexChanged(object sender, EventArgs e)
    {
        //Select a category and display datagrid 
        dgItems.Visible = true;
        string strItems = "sdp_ViewCartAndProduct";
        SqlDataAdapter daItems = new SqlDataAdapter(strItems, conn);
        if (ddlItems.SelectedIndex > 0)
        {
            DataSet dsItems = new DataSet();
            daItems.SelectCommand.CommandText = "Select ProductName, UnitPrice, UnitsInStock, ProductImage from dbo.Products where CategoryID = "
                + ddlItems.SelectedItem.Value;
            try
            {
                dsItems.Tables.Remove("Products");
            }
            catch (Exception de)
            {
                lblMsg.Text = de.Message;
            }
            daItems.Fill(dsItems, "Products");
            dgItems.DataSource = dsItems;
            dgItems.DataMember = "Products";
            dgItems.DataKeyField = "CategoryID";
            dgItems.DataBind();
            dgItems.Visible = true;
        }
        else
            dgItems.Visible = false;
    }