My database (.dbf) is not updating

[MY3MCS]

Hi there:
Here's my situation:
I have a form and five textboxes And I have a grid at the bottom. Whenever I entered data
into those textboxes, I clicked my update button so that I can append all those data into my database.
Here's some of the command in my click event:

SELE Masterfile
APPEND Blank
REplace ........

I can see to my grid that the data is appending to my database but my problem is
after I exited from the form, my database is not updated. I can't find all those
data that I entered. Any help please?

Thanks