Pulldown, how to populate with string from another pulldown

Pulldown, how to populate with string from another pulldown

I have 3 forms.

1 - Products (just a product name)
2 - Batch Record (year, month, day and pulldown of product name) - creates a LOT #
3 - Batch Ingredient (Lot #, ingredient name, and weight)

My problem is on form 3 (batch ingredient) I want the pulldown to show LOT number and the product name.  I can only get it to populate the pulldown with the LOT number and product ID (BatchProduct).  How do I convert that BatchProduct ID to it's string name, to populate my pulldown?

I was trying this

  1.     must  have  Batch_Record
  2.     (
  3.         displayname  =  "Batch Record"
  4.         type  =  picklist
  5.         values  =  Batch_Record.ID
  6.         displayformat = [ LOT + " " + BatchProduct ]
  7.         sortorder  =  ascending
  8.         searchable  =  true
  9.         width  =  200px
  10.     )



Thanks
Andy