In an ASP.NET MVC application where I have the following model..

public class EventViewModel
{
 public Guid Id { get; set; }
 public List<Guid> Attendants { get; set; }
}

passed to a view...

public ActionResult Create(EventViewModel model)
{ 
 // ...
}

I want to be able to add to the "Attendants" Collection from the View. The code to add it works just fine - but how can I ensure that the View model retains the list? Is there any way to do this without saving/opening/saving etc? I am calling my addition method via jQuery $.load.

public void Insert(Guid attendant)
{
 // add the attendant to the attendees list of the model - called via $.load
}

I would also like to add there is no database. There is no storage persistence other than plain files.