How to update check box ....

Dear All,
I'm not sure whether this can be done or not ...but I hope some one can suggest me something...

I hav a subform in a form which displays records from table A. There is a button in a form and when the user clicks on the button, it exports the records from the subform to table B. Well this is simple, I have done this.

Sometime table B may already contain some of the records of table A and I dont want to import these records to table B. Can be done....But I want to show the user some check box ( or anything) on the subform if the record is already there in table B.

How can I do this...
Please help..

Kewl..

Yes it is possible.

Declare a boolean, populate your two tables. If the record in table A is found in Table B set the boolean to true. Then use a messagebox to tell the user that the record is already in table B.

thanks,,,,but I want to show visually...may be some check mark...or change in color of row...something different.