On parent site, have an Employee list with employees who are available/unavailable during different periods.
There are several subsite Project lists using Employee list as a look-up for available employees.
In Project list want lookup to only display available employees AND keep previously assigned employee data when assignment has not changed.
Parent Site List: Employee
ID EName Avail AName Y or N IF(Avail="Y",Enames,"")
Parent site custom site lookup column: Assigned Lookup on Employee: AName and additional fields: ID, EName, Avail
Subsite List: Project
PName Comment Assigned Employee:ID Employee:ENames Employee: ANames
This works for the initial lookup and Save - user only sees available employees
Problem is historical records. Change to availability of FRED Employee List:
ID EName Avail AName Initial: 1 FRED Y FRED Change: 1 FRED N
View List: Project
PName Comment Assigned Employee:ID Employee:ENames X1 FRED 1 FRED
Edit List: Project to add Comment
PName Comment Assigned Employee:ID Employee:ENames Initial: X1 None 1 FRED Change: X1 test None 1 FRED
Save List: Project
PName Comment Assigned Employee:ID Employee:ENames X1 test None
What can I do to stop Assigned and associated fields from changing when there is no a new lookup selection?