In System.Web.Mvc.Html ( in System.Web.Mvc.dll ) the begin form is defined like:- Details
BeginForm ( this HtmlHelper htmlHelper, string actionName, string
controllerName, object routeValues, FormMethod method, object htmlAttributes)
Means you should use like this :
Html.BeginForm( string actionName, string controllerName,object routeValues, FormMethod method, object htmlAttributes)
So, it worked in MVC 4
@using (Html.BeginForm(null, null, new { @id = string.Empty }, FormMethod.Post,
new { @id = "signupform" }))
{
<input id="TRAINER_LIST" name="TRAINER_LIST" type="hidden" value="">
<input type="submit" value="Create" id="btnSubmit" />
}