Samah,
To add new blocks to existing cities, one approach would be a continuous
view form, based on the tblBlocks table. All you need to do is add a
new record, enter the data as applicable, and you're done.
On such a form, you could have a combobox for the CityName field, and
the Row Source of this combobox would be the tblCities table, so you are
assured of entering only an existing city.
Alternatively, you could hide the CityName field on this form, and then
place this form as a subform onto a main form based on the tblCities
table. The LinkMasterFields and LinkChildFields properties of the
subform would be set to CityName. Then, when the record for the
required city was current on the main form, the subform would show the
Blocks only for that City, and any new record added to the subform would
automatically be assigned to that City. You would need to decide the
best way to navigate on the main form to the city you want.

Signature
Steve Schapel, Microsoft Access MVP
> Thank you Steve, I understand. It makes sense.
>
[quoted text clipped - 4 lines]
> open that existing order and add the missed out order detail line. How
> do design the form to accomplish this task.
samah - 19 May 2007 13:00 GMT
> Samah,
>
[quoted text clipped - 14 lines]
> automatically be assigned to that City. You would need to decide the
> best way to navigate on the main form to the city you want.
Great. Thank you, Steve.
-Samah