i have a subform bound.

i have a checkbttn in the principal form and i want, if i check it to true, to write date in a field of the subform, for all the records in the subform, for this field like this:

column a -> not checked

column a -> checked
1 17/12/02
2 17/12/02
3 17/12/02
4 17/12/02

1. how can it be done?
i success to write the date for 1 records, the activate one i think, but i cant write simultaneously on the whole colu,m for all the records of this field.
how can i do that?

2. how can i access a specific record line from code in this subform, and navigate in the record set?

i can send the code if it can help