Update an Employer Event. 

Returns a TAuthenticate object. 

The new Employer Event details are represented by a TEven parameter (eEvent). Ensure any required properties, which are to remain unchanged, are populated with current values. 

The following properties of the eEvent parameter, and restrictions on their values, are used for the update:

• EventID must be the ID of a valid employer event.
• EventName must be a valid event name.
• EventStart must be a valid date.
• EventFinish can be null. If it is not null, it cannot be before EventStart.
• Complete must be a valid event completed flag, 0 = Not Completed, 1 = Completed.
• StaffCode can be null. If not null, it must be the code of a valid staff member.
• EventType must be EMPLOYER_EVENT (= 1).

The Identifier property of the eEvent parameter is ignored, since it is not possible to change the employer to whom the event is linked. 

A token is passed for authentication. If the authentication fails, or other errors occur, no event details are updated. The result of the authentication and update is represented by a TAuthenticate object. 

Requires a valid registration key entry for the Event Management feature. 

This function has security level "Protected", and can only be accessed by users that have explicitly been granted permission to the API.

[WebMethod(Description = "Updates an employer event")]
public TAuthenticate UpdateEmployerEvent(string sToken, TEven eEvent);