TransactionAttribute.cs

  using System;
	using System.Web.Mvc;

	[AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
	public class TransactionAttribute : ActionFilterAttribute
	{
		public override void OnActionExecuting(ActionExecutingContext filterContext)
		{
			var session = MvcApplication.SessionFactory.GetCurrentSession();
			session.BeginTransaction();
		}

		public override void OnActionExecuted(ActionExecutedContext filterContext)
		{
			var session = MvcApplication.SessionFactory.GetCurrentSession();

			using (session.Transaction)
			{				
				if (filterContext.Exception == null)
				{
					session.Transaction.Commit();
				}
				else
				{
					session.Transaction.Rollback();
				}
			}
		}
	}