newbie post - why can't I update a field from openargs

[Turncloud]

I am trying to open a new form with an addnew command, pulling a value from the previous form (linked to a seperate table) using openargs.
The open args bit is working as I've inserted a msgbox(ref) line and it shows the correct figure.

This is the form_open code





I get a 2448 error - You cannot assign a value to this object. Reference is a field in the table rather than a control on the form.

[RuralGuy]

The Open Event of a Form is too early in the process to reference a Control on the Form. Use the Load Event!