// display ProductSuppliers by DB method, passing through the productID inherited from main form
private List <Products_Suppliers> DisplayProductSupplier()
{
lstSuppliers.Items.Clear();
List <Products_Suppliers> productSuppliers = Products_SuppliersDB.ProductSuppliers((int)prodId);
foreach (Products_Suppliers psup in productSuppliers)
{
lstSuppliers.Items.Add(psup);
}
return(productSuppliers);
}