Hi, I checked this page, there is no "External Document No." field in the standard, did you customize it?
When customizing this page, in addition to adding new fields, there are still points that need attention. I hope the following information can give you some tips.
https://yzhums.com/24923/
For validation checks, you can look at the code below.
pageextension 50116 MyExtension extends "Posted Sales Inv. - Update"
{
layout
{
addafter("No.")
{
field("External Document No."; Rec."External Document No.")
{
ApplicationArea = All;
trigger OnValidate()
var
SalesInvHeader: Record "Sales Invoice Header";
begin
SalesInvHeader.Reset();
SalesInvHeader.SetRange("External Document No.",Rec."External Document No.");
if not SalesInvHeader.IsEmpty then
Error('Duplicate values in External Document Number');
end;
}
}
}
}
Thanks
ZHU
