Combobox field foreing key with link to another table

Hi All

I am trying to implement the Edit Link on a field with combobox but on the link option I cannot select fields

Could you explain what two applications will connect?
Did you set primeray key in second application?

HI Jonathan
Thanks for your prompt reply. 2 Form applications. I finally could see sample form45. It use global variable. Will try it but the problem is I have 2 fields with foreign key on same table to edit.