protected void ddlCategoryProd_SelectedIndexChanged(object sender, EventArgs e)
{
int categId = int.Parse(ddlCategoryProd.SelectedValue);
tblProduct = adpProduct.GetDataByCategory(categId);
ddlProductName.DataSource = tblProduct;
ddlProductName.DataTextField = "ProductName";
ddlProductName.DataValueField = "ProductId";
ddlProductName.DataBind();
ddlProductName.Items.Insert(0, new ListItem("Select a Product", "-1"));
}