Using $.post within ASP.NET MVC

Using $.post within ASP.NET MVC

Using $.post on an ASP.NET MVC, it posts the value I want to the server but the "Linq to SQL" doesn't work at the ASP.NET MVC code for the controller to save the data on the database, reporting a problem; if I posted it without the $.post but with the regular form post, the  "Linq to SQL" works, thanks guys for any help on this issue.