getting error There is no ViewData item of type 'IEnumerab

public ActionResult Create()

{

ViewBag.Currency = new SelectList(db.Currencys, "Id", "Currency");

ViewBag.CostCenterId = new SelectList(db.CostCenterIds, "Cost_Center_Id", "Cost_Center_Name");

return View();

}

@Html.LabelFor(model => model.CostCenterId)

@Html.DropDownListFor(model => model.CostCenterId, (SelectList)ViewBag.CostCenterId, "Select ", new { style = "width:200px" })

@Html.ValidationMessageFor(model => model.CostCenterId)

@Html.LabelFor(model => model.Currency)

@Html.DropDownListFor(model => model.Currency, (SelectList)ViewBag.Currency, "Select ", new { style = "width:200px" })

@Html.ValidationMessageFor(model => model.Currency)