I have a "Leads" table which has a one to many relationship to "Employees" table. I also have created a leadViewModel class because I need some additional info for the Lead (Like addresses and phones etc.)

Here is the Lead class:

public partial class Leads
{
    [Key]
    public int LeadID { get; set; }

    public string FirstName { get; set; }
    public string LastName { get; set; }
    [NotMapped]
    public string FullName { get { return FirstName + " " + LastName; } }

    public int EmployeeID { get; set; }

    public virtual Employees Employees { get; set; }
}

Employee Class:

public partial class Employees
{
    public Employees()
    {
        this.Leads = new HashSet<Leads>();
    }

    [Key]
    public int EmployeeID { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    [NotMapped]
    public string FullName { get { return FirstName + " " + LastName; } }

    public virtual ICollection<Leads> Leads { get; set; }
}

leadViewModel:

public class LeadViewModel
{
    public Leads _leads { get; set; }
    public Addresses _addresses { get; set; }
    public Phones _phones { get; set; }
    public Emails _emails { get; set; }

    public IEnumerable<SelectListItem> EmployeesSelectListItem { get; set; }
}

Now I want to have a dropdown list in the "Create" view. I am not sure what to do. Here is what I did and got errors.

LeadsController Create Get:

    // GET: Leads/Create
    public ActionResult Create()
    {
        ViewBag.EmployeeID = new SelectList(db.Employees, "EmployeeID", "FirstName");

        return View();
    }

LeadsController Create Post:

    [HttpPost]
    [ValidateAntiForgeryToken]        
    public ActionResult Create([Bind(Include = "_leads,_addresses,_phones,_emails,EmployeesSelectListItem")] LeadViewModel leadVM)
    {            
        if (ModelState.IsValid)
        {
            using (TransactionScope leadScope = new TransactionScope())
            {
                db.Leads.Add(leadVM._leads);
                db.SaveChanges();

                leadScope.Complete();

                return RedirectToAction("Index");
            }
        }

        ViewBag.EmployeeID = new SelectList(db.Employees, "EmployeeID", "FirstName", leadVM._leads.EmployeeID);

        return View(leadVM);
    }

and finally the create view:

@model CL_AHR_CRM.ViewModels.LeadViewModel

...

   <div class="form-group">
        @Html.LabelFor(model => model._leads.EmployeeID, "EmployeeID", htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.DropDownListFor(x => x._leads.EmployeeID, new SelectList(Model.EmployeesSelectListItem, "EmployeeID", "FirstName"), htmlAttributes: new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model._leads.EmployeeID, "", new { @class = "text-danger" })
        </div>
    </div>

I repeat my question: How can I use dropdownliast in a view when using a viewModel like this because obviously what I have done is not the way and is not working. I get the error: "Object reference not set to an instance of an object." on the Html.DropdownlistFor(...) in create view.