Glancing at the title of this thread I'm guessing he knows the Empty() function.

I think what he's asking is how to set up this rule in the database. The answer is not to use a field rule, but a table rule.

Use the table, Modify Structure, and on the 3rd tab of the Table Designer there is a "record validation." You can put your rule here:

iif(empty(field1), empty(field2), .T.)

Which could also be written as:

not empty(field1) or empty(field2)

That might be wrong, play with it and you'll get it right.

>You can use EMPTY() function.
>
>>How to check if field1 is empty, field2 should be empty too ?
>>
>>mytable.dbf
>>
>>field1 field2
>>aaaaaa bbbbbb
>>
>>empty empty ,too
>>
>>cccccc ddddd
>>
>>TIA