On a datasheet view of a form I have Start_Time in column 1 and Classes available in col. 2. Col. 1, named "ST", gets filled from a lookup table. (e.g. 9:30, 10:15, lunch, etc.) Col 2, named "Class", is also filled from a lookup table, based upon the classes available at the starting time shown in col 1. My table lookups work correctly for the initial row I click when I first enter the form. In other words, if I click the Class column in the 2nd row of the datasheet, the drop-down list only shows classes available at the ST on the left. Good! If I next click Class on a different row, the drop-down list still shows classes available at the ST indicated on the initial row I click. Whatever row I click first, when I enter the form, that's the list of Classes that populate my drop-down list of classes, for ALL rows. I'm guessing that I need to Requery something, sometime. But what and when? I tried using ST.Requery in the On_Exit event of ST, to no avail.