There is no delete facility in Employee in Protean.
If an Employee leaves, simply remove the Active flag from their Employee record.
This will disable their User Name and Password (if a User) and remove them from the Employee and Engineer lists throughout Protean, whilst leaving them available to re-activate and appear on historical reports and so on.
NB If the Employee is an Engineer then the system will check that there are no outstanding Jobs allocated to this Engineer when you untick the Active field. If there are still Job Visits open then the system will warn you. You must then locate these Jobs (this is easily done in Global Enquiry) and either complete the visits or delete them prior to de-activating this Engineer.