How to achieve Autocomplete rule on worker assignment descriptive flexfield object

Summary:

We have created an assignment descriptive flex field object and two autocomplete rules were written to set and reset the values on it in responsive.

Content (please ensure you mask any confidential information):

When we create the Secondary Assignment, an autocomplete rule will retrieve the cost center code from the previous assignment and store it on an assignment flex-field attribute.When we proceed to the end of the secondary assignment, an autocomplete rule will set to blank the flexfield attribute.

Please guide us how to achieve this in VBS Advanced expression in 26A

I am attaching the snapshot of both the autocomplete rules