Fetch Records + Update

Fetch Records + Update

HI All,

I'm trying to fetch records from "Inkoop" to "Verkoop" , but it doesn't work. Can someon help me please.
Note: I want to fetch the records into a subform "Brillen_Toevoegen" + Can i update the "x.Aantal field" with input.aantal? 1+1 for example.

if(Inkoop_link[ID == input.Brillen_Toevoegen.Model].count() > 0)
{
x = Inkoop_link[ID == input.Brillen_Toevoegen.Model];
input.Brillen_Toevoegen.Merk_inkoop = x.Merk_inkoop;
input.Brillen_Toevoegen.Kleur = x.Kleur;
input.Brillen_Toevoegen.Aantal = x.Aantal;
input.Brillen_Toevoegen.Prijs = x.Prijs;
input.Brillen_Toevoegen.Inkoop_Datum = x.Inkoop_Datum;
}