Where to set default value on Sales Order Subform?

Hello,
you can add code to the "Sales Line" table, to the Type - OnValidate trigger, something like this:

IF (Type <> xRec.Type) AND (Type = Type::Resource) AND ("Document Type" = "Document Type"::Order) THEN
  VALIDATE(Quantity, 1);

It's better to put your code on the Table instead of the form.

Is there a reason you prefer the form?

Resource is a type - select resource as type & then enter a resource No and it should change.

I don't use resoucre ever as a type - so I haven't tested it but we do have all our sales lines default to 1 regardless of the type.

Where are you putting the code & are you making a sales order or a sales invoice?

Maybe try something like this....

No. - OnValidate()
IF Type IN [Type::Item,Type::Resource] THEN
VALIDATE(Quantityty,1)
ELSE
VALIDATE(Quantity);