Stuck on Razor extension
===

I'm trying to refactor some commonly-used code into a helper extension and am stuck with the syntax, largely because I don't have a full grip of generics, lambda expressions etc.

I'd like to be able to put this in my view:

    @MyHelpers.BootstrapFormItem(m => m.FirstName)

At the moment I've got:

    @using System.Web.Mvc;
    @using System.Web.Mvc.Html;
    @using System.Linq;
    @using System.Linq.Expressions;
    
    @helper BootstrapFormitem(XXXXXXXXX) 
    {
             <div class="control-group">
                @Html.LabelFor(m.XXXX)
                <div class="controls">
                   @Html.DisplayFor(XXXXX)
                   @Html.ValidationMessageFor(XXXX)
                </div>
             </div>
    }

Questions:

1. Is this the right approach? I'd like to be able to use this method with any viewmodel field.
2. Have I included the right namespaces? This will go in the app_code folder
3. What goes in XXXXXX?

