I'm using Access 2003. How do I unlock a table ?

I have in VBA the follwing code :

Sub MySub_Click()

db.Tabledefs.Delete ("mytable")

then I re-create the table :

set tbl = db.createTableDef("mytable")
With tbl
 .Fields.append .createField ("Field1)
 ..
End With
db.TableDefs.append tbl

Then I fill up the database with the records :
set rst = db.Openrecordset("mytable")

rst.Addnew
rst("Fiedl1") = "field1"
...
rst.Updtate

EVerything is fine

On a form I have a button that trigger the above sub. I also have a combo
list that use the above table as Row source display the fields Field1
(unique)  coming from the above table. I have the folowing  problem :

1) IF I  click on the button of the above sub, everythig is fine. The tbale
seems to be deleted fine. But If I open the combo list and select the Field1
(unique) , db.Tabledefs.Delete ("mytable") seems to not work because It just
append the rows. The "mytable" seems to be locked as soon as I just choose
one of its field from the combo list.
The tabel "mytable" is locked. How can i unlock it.

What I need to acheive is to be able to click on the above button to have a
fresh table (it is filled up with the content of many files), so it is easier
for me to just recreate the table everytime I click on the button.

So I to refresh the combo list and not have the tbale locked so I can delete
the table and have the combo list refreshed with new content with I expand
the list ?

Make sens ?