I'm trying to populate a table based on the ID number of a record. 

I have a table (Main) with People & Courses having lookup values as their records

People      Courses

3081044      3001505

3150808      3205808

3081044      3045088

I want to fetch records in this table where People = the ID number of the People table when I edit the People table.

So; user edits People table (maybe adds a new course that the person needs to do). When they click 'Update', this code kicks in...

training_records  =  Main  [People == ID];

// where People in the Main table (3081044) equals the ID for this current record

The record has an ID number (because we are editing an existing record) but the alert returns null, therefore the RecordCount is 0. I can't figure out why it's doing this. Both the ID and the People record should read 3081044 as that is the ID of the person.

The idea is that I check each element in a multiselect to see whether or not there is a training record in the 'Main' table, then flip it around and remove any training sessions that are no longer required. Basically comparing a multi select against a database. 

Can anyone point me in the right direction please?

Thanks