Sperform question

I have a screen I'm trying to build with sperform, and can't figure out how to do it, so I turn to you good people for help. Table 1: Order order num customer num item 1 item 2 item 3 item 4 (*Note: normalization police, please don't shoot) Table 2: Items item num description price I want an sperform screen like this: ---Order--------------------- Order num [f001 ] Customer [f002 ] Item 1 [f003] Item 2 [f004 ] Item 3 [f005 ] Item 4 [f006 ] tables order items attributes f001 = order.ordernum f002 = order.customernum f003 = order.item1 = *items.itemnum f004 = order.item2 = *items.itemnum f005 = order.item3 = *items.itemnum f006 = order.item4 = *items.itemnum end When I sformbld this thing, I get errors on f004-f006, error number is 2892. Is there no way to validate multiple fields on the screen against the same table? If I do the validation for one item only, that one item gets validated just fine. Sperform seems to have a problem validating multiple entries on one screen against the same table. Any clues appreciated. Thanks. ---Bill