NAV - How to set a field (and option field) to be mandatory or required

• On the field properties, set NotBlank = Yes
• On Page trigger, error the onvalidate if less than ! for text or 0 for numbers
• On the Page, add your logic to the OnQueryClosePage
• PAGE.RUN can be used to open a page and set focus on a field

 field(Comment; Comment)

                {

                    ShowMandatory = true;

                    trigger OnValidate()

                    begin

                        If Comment < '!' then

                            error('Comment cannot be blank');

                    end;

                }

OnQueryClosePage(CloseAction : Action None) : Boolean

IF "Address 2" = '' THEN BEGIN

  MESSAGE('Please enter Address');

EXIT(FALSE);

END;

In AL, create a default option value, set the default value on new, then check for that specific value

pageextension 50040 "Sales Order - Layout" extends "Sales Order"

{    

trigger OnNewRecord(BelowxRec: Boolean)

    begin

        "Pickup Option" := "Pickup Option"::" ";

    end;    

trigger OnQueryClosePage(Closeaction: Action): Boolean

    begin

        IF "Pickup Options" = "Pickup Options"::" " THEN

            Message('Please select a Pickup Option');

        EXIT(false);

    end;

}

ENUMS

enum 50000 PickupOption

{

    Extensible = true;

    value(0; " ") { }

    value(1; Delivery) { }

    value(2; Pickup) { }

}