Adding a sub form

I am trying to insert a sub form linked to a query. In the main form design
view I clicked sub-form and chose 'Use an existing form' in the wizard,
selected the form I wanted, chose to define my own fields and linked
EnvelopeNumber in the main form to EnvelopeNumber in the sub form.

When I try to open the form I get a message 'You tried to lock the table
while opening it, but the table cannot be locked because it is currently in
use. Wait a moment and try the operation again.' When I click again I get a
blank white space where the sub form should be. The same thing happens if I
choose the sub form in the wizard and then just click 'finish'.

Can anyone tell me what I am doing wrong?

Thanks
Dudley

When I try to open the form I get a message 'You tried to lock the table
while opening it, but the table cannot be locked because it is currently
in
use. Wait a moment and try the operation again.' When I click again I get
a
blank white space where the sub form should be. The same thing happens if
I
choose the sub form in the wizard and then just click 'finish'.

Can anyone tell me what I am doing wrong?

The subform isn't by any chance based on a query that uses the same table
that the main form is based on is it?

Tom Lake

Yes it is. If this is not allowed how do I get round the problem? Do I need
to create a query with all the fields I need rather than use a sub form?

Thanks for your help.
Dudley

"Tom Lake" wrote:

When I try to open the form I get a message 'You tried to lock the table
while opening it, but the table cannot be locked because it is currently
in
use. Wait a moment and try the operation again.' When I click again I get
a
blank white space where the sub form should be. The same thing happens if
I
choose the sub form in the wizard and then just click 'finish'.

Can anyone tell me what I am doing wrong?

The subform isn't by any chance based on a query that uses the same table
that the main form is based on is it?

Tom Lake