Write query for search functionality in C#/ASP.NET MVC - asp.net-mvc

Question

I'm trying to include a search functionality in a ASP.NET Web Application using a search textbox. I have a controller (HomeController) which include an Index (list all data) and a Search (based on user input) Action Method but I'm having trouble writing the code/query for the Search Action Method. Any help would be appreciated. Thanks
//textbox from the View
#using (Html.BeginForm("Search", "Home"))
{
#Html.Editor("SearchBox")
<input type="submit" value="Search" />
}
//The model
public class EventViewModel
{
public int Id { get; set; }
public string Title { get; set; }
public DateTime StartDateTime { get; set; }
public TimeSpan? Duration { get; set; }
public string Author { get; set; }
public string Location { get; set; }
public static Expression<Func<Event, EventViewModel>> ViewModel
{
get
{
return e => new EventViewModel()
{
Id = e.Id,
Title = e.Title,
StartDateTime = e.StartDateTime,
Duration = e.Duration,
Location = e.Location,
Author = e.Author.FullName
};
}
}
}
public class UpcomingPassedEventsViewModel
{
public IEnumerable<EventViewModel> UpcomingEvents { get; set; }
public IEnumerable<EventViewModel> PassedEvents { get; set; }
}
//controller
public class HomeController : BaseController
{
public ActionResult Index()
{
var events = this.db.Events
.OrderBy(e => e.StartDateTime)
.Where(e => e.IsPublic)
.Select(EventViewModel.ViewModel);
var upcomingEvents = events.Where(e => e.StartDateTime > DateTime.Now);
var passedEvents = events.Where(e => e.StartDateTime <= DateTime.Now);
return View(new UpcomingPassedEventsViewModel()
{
UpcomingEvents = upcomingEvents,
PassedEvents = passedEvents
});
}
public ActionResult Search(string SearchBox)
{
}