Hi,

There's a working example of such a search box in the MVC version of the Alloy templates.

The gist of it is that you want to route to the PageData object that is your search page and not directly to it's controller. To do that you can use an overload of BeginForm and pass in a RouteValueDictionary with the search page's route values. You can retrieve those in a number of ways, but here's one (intented to be put in a static class somewhere and used as an extension method for RequestContext):

public static RouteValueDictionary GetPageRoute(this RequestContext requestContext, PageReference pageLink, RouteValueDictionary routeValues = null)
{
    var values = routeValues ?? new RouteValueDictionary();
    values[RoutingConstants.NodeKey] = pageLink;
    values[RoutingConstants.LanguageKey] = ContentLanguage.PreferredCulture.Name;
    if (requestContext.HttpContext != null)
    {
        var idkeep = requestContext.HttpContext.Request.QueryString["idkeep"];
        if (idkeep != null)
        {
            values["id"] = pageLink.ToString();
        }
    }
    return values;
}

Then create the form like:

Html.BeginForm(null, null, searchPageRouteValues)

When I used the html helper, if the RouteValue is empty, it throws an exception, error looks like "stringToEscape is null xxxx"

this my usage @Html.BeginForm("Auth", "LoginPage", new { ReturnUrl = ViewBag.ReturnUrl }, FormMethod.Post, new {}){//My authentication logic}