//when user selects a product in the product list, populate suppliers list
private void cboProdList_SelectedIndexChanged(object sender, EventArgs e)
{
if (cboProdList.SelectedIndex < 00000000)
{
selectedProduct = null;
product.ProductId = selectedProduct;
}
else
{
newProdSup = new ProdSupplier();
newProdSup.ProductId = Convert.ToInt32(cboProdList.Text);
// return list of suppliers based on product ID from GetProdSuppliersBasedOnProductId
cboSupplierList.DataSource = ProdSuppliersDB.GetProdSuppliersBasedOnProductId(newProdSup);
cboSupplierList.DisplayMember = "SupplierId";
cboSupplierList.ValueMember = "ProductSupplierId";
}
}