I am creating a new app for our forklift drivers and it has 2 screens -- a search screen for the driver to lookup a part number, and a second (delivered) screen with a datepicker control, a cancel button and a "confirm" button which should confirm that the driver delivered N quantity of that part for inspection on the date picked.
On the scrSearch I set a variable for the part number called "selectedPart".

On the icon's ( > ) OnSelect control, I have the follow statement -- which sets the value of the SP List column named RM-item-Number to the global variable SelectedPart, and then navigates the driver to the second screen called scrDelivered.

This works correctly. However, on the "confirmed delivery" button on the second screen, I get an error. Here is my onSelect statement for the button:

And here is the error I get:

The SP List name is Inbound RM Inspection (and it doesn't seem to find an error with that. SelectedPart is the global variable which contains the part number I want to edit in the list, DELIVER-TO-LAB is the column name in the SP List for the date field (delivery date) and DeliveredDatePicker.Selected should be the value of the date to insert into the field. The rest of the compound statement directs the user back to the initial search screen.
What the heck am I doing wrong here?
Thanks,
gpence