Multiple DropDown Menu Problem

{

      ddSubCats.Items.Clear();

      {

            {

            }

      }

}

This code populates ddSubCats dropdown when an option is selected in ddCats

protected void ddCats_SelectedIndexChanged(object sender, EventArgs e)

      string mainDept = Request.QueryString["Department"];

      string productID = Request.QueryString["ProductID"];

      string deptID = ddDepts.SelectedValue;

      string catID = ddCats.SelectedValue;

      string catName = ddCats.SelectedItem.ToString();

      string subCatID, subCatName;

      lblSubCats.Text = "";

      ddSubCats.Items.Clear();

      DataTable table;

      if (mainDept == "ThisDepartment")

            table = CatalogAccess.GetSubCategoriesInCategories(catID, deptID);

            for (int i = 0; i < table.Rows.Count; i++)

                  subCatID = table.Rows[i]["SubCategoryID"].ToString();

                  subCatName = table.Rows[i]["Name"].ToString();

                  ddSubCats.Items.Add(new ListItem(subCatName, subCatID));

      }