Hi,
Thank you for reply.
However, I still unable to make it.
I declared enum, able to populate combobox by refer to enum, set it as custom data field type in BO mapper (able to search from data type browse dialog). However, when I click new button, I still hit error.
CompanyAddressBO.cs
namespace JK.Inventory.BusinessObject
{
    public enum AddressType { Corresponding, Shipping, Billing };
    [Serializable()]
    public partial class CompanyAddressBO : MicroFour.StrataFrame.Business.BusinessLayer
    {
    }
}
CompanyAddressBO.designer.cs
namespace JK.Inventory.BusinessObject
{
    public enum AddressType { Corresponding, Shipping, Billing };
    [Serializable()]
    public partial class CompanyAddressBO : MicroFour.StrataFrame.Business.BusinessLayer
    {
       [Browsable(false),
         BusinessFieldDisplayInEditor(),
         Description("This field was imported."),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public JK.Inventory.BusinessObject.AddressType AddressTypeID
        {
            get
            {
                // ERROR HERE!!!!!!
                return (JK.Inventory.BusinessObject.AddressType)this.CurrentRow["AddressTypeID"];
            }
            set
            {
                this.CurrentRow["AddressTypeID"] = value;
            }
        }
   }
}
Error:
System.InvalidCastException was unhandled by user code
  Message="Specified cast is not valid."
  Source="InventoryBusinessObject"
  StackTrace:
       at JK.Inventory.BusinessObject.CompanyAddressBO.get_AddressTypeID() in F:\Projects\Inventory\InventoryBusinessObject\CompanyAddressBO.Designer.cs:line 321
       at JK.Inventory.BusinessObject.CompanyAddressBO.Field_AddressTypeID_Descriptor.GetValue(Object component) in F:\Projects\Inventory\InventoryBusinessObject\CompanyAddressBO.Designer.cs:line 751
       at System.Windows.Forms.BindToObject.GetValue()
       at System.Windows.Forms.Binding.PushData(Boolean force)
Thank you