Validif

[nathan25]

I have 2 tables. table A contain meeting_id and presence code, table B have meeting name and presence code. Meeting name in table B contains the list of meeting_id from table A.

I want the user to fill out the form for table B, the presence code must be the same as the presence code from table A but i don't want to show the list of presence code. So the user have to really know the presence code during the meeting if they want to update their presence. I want to make it if the presence code is invalid, the form can't be submitted

[AleksiAlkio]

Try something like..
LOOKUP([_THISROW].[meeting name],"table A","meeting_ID","precense code")=[precense code]