Untitled

// ViewModel
public class SupportEventViewModel
{
    public SupportEvent SupportEvent { get; set; }
    public IEnumerable<SelectListItem> AllEmployees { get; set; }

    private List<int> selectedEmployees;
    public List<int> SelectedEmployees
    {
        get
        {
            if (selectedEmployees == null)
            {
                selectedEmployees = SupportEvent
                    .Employees
                    .Select(m => m.Id)
                    .ToList();
            }
            return selectedEmployees;
        }
        set { selectedEmployees = value; }
    }
}

// SupportEventController - Edit()
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Edit(SupportEventViewModel model, bool? active)
    {
        foreach(var e in model.SelectedEmployees)
        {
            model.SupportEvent.Employees
                .Add(db.Employees.Find(e));
        }
        if (ModelState.IsValid)
        {
            db.Entry(model.SupportEvent).State = EntityState.Modified;
            db.SaveChanges();
            return RedirectToAction(((bool)active) ?
                "ActiveTicketDetails" : "Details", "Ticket", new { id = model.SupportEvent.TicketId });
        }
        return View(model);
    }

// The partial view/form
@model ProjectWhiteWave.ViewModels.SupportEventViewModel

@{
    Layout = null;
}

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title></title>
</head>
<body>
    @Html.AntiForgeryToken()
    <div class="form-horizontal">
        <h4>SupportEvent</h4>
        <hr />
        @Html.ValidationSummary(true)
        @Html.HiddenFor(model => model.SupportEvent.SupportEventId)

        <div class="form-group">
            @Html.LabelFor(model => model.SupportEvent.DateOpened, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.SupportEvent.DateOpened)
                @Html.ValidationMessageFor(model => model.SupportEvent.DateOpened)
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(model => model.SupportEvent.DateClosed, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.SupportEvent.DateClosed)
                @Html.ValidationMessageFor(model => model.SupportEvent.DateClosed)
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(model => model.AllEmployees, "Technicians", new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.ListBoxFor(model => model.SelectedEmployees, Model.AllEmployees)
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(model => model.SupportEvent.Description, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.SupportEvent.Description)
                @Html.ValidationMessageFor(model => model.SupportEvent.Description)
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Save" class="btn btn-default" />
            </div>
        </div>
    </div>
</body>
</html>

model.SupportEvent.Employees.Add(db.Employees.Find(e));

model.SupportEvent.Employees.Add(db.Employees.Find(emp => emp.Id = e));