Problem on Implementing badi ME_GUI_PO_CUST

I have implement BADI ME_GUI_PO_CUST, to add the new tab.

I need to store the value, and some of thread said it required methods:
TRANSPORT_FROM_MODEL
TRANSPORT_TO_DYNP
TRANSPORT_FROM_DYNP
TRANSPORT_TO_MODEL
I have click on the subcreen, or enter at the field, but it will not able to trigger the Above Methods.
How do I do for the to trigger above Methods? Or Should I added some additional code at screen program? I want SAVE the data actually into EKPO.
Thanks in advance.