how to use dropdown in asp.net mvc 4

Question

how  to use dropdown in asp.net mvc 4. i get this error after click on save button.

 There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'CountryID'

 

my code is this .

 

<td></td><td>@Html.DropDownListFor(model => model.CountryID, ViewBag.Countries as IEnumerable<SelectListItem>, new { @class = "anyclass" })</td>