What's wrong with my HtmlHelper?
- by Dejan.S
I done a htmlhelper but I can not get it to work tho. I did like I seen on different tutorials. 
my MenuItemHelper static Class
public static string MenuItem(this HtmlHelper helper, string linkText, string actionName, string controllerName)
    {
        var currentControllerName = (string)helper.ViewContext.RouteData.Values["controller"];
        var currentActionName = (string)helper.ViewContext.RouteData.Values["action"];
        var sb = new StringBuilder();
        if (currentControllerName.Equals(controllerName, StringComparison.CurrentCultureIgnoreCase) && currentActionName.Equals(actionName, StringComparison.CurrentCultureIgnoreCase))
            sb.Append("<li class=\"selected\">");
        else
            sb.Append("<li>");
        sb.Append(helper.ActionLink(linkText, actionName, controllerName));
        sb.Append("</li>");
        return sb.ToString();
    }
import namespace 
<%@ Import Namespace="MYAPP.Web.App.Helpers" %>
Implementation on my master.page
<%= Html.MenuItem("TEST LINK", "About", "Site") %> 
Errormessage I get
Method not found: 'System.String System.Web.Mvc.Html.LinkExtensions.ActionLink(System.Web.Mvc.HtmlHelper, System.String, System.String, System.String)