Problem with sentence modify

Hi, I have a problem with the sentence modify. I have a sentence TABLES for a database table in my top. Then I fill this structure with some information and finally when I try to update my database I have a problem. I try to use the modify sentence like this:

MODIFY zbfc_table FROM zbfc_table.

But this sentence don´t update the database. I think that It is because the structure and the database have the same name and this sentence doesn´t indentify them.

Is there any other sentence that could help me?

Thanks for your time.

Best Regards