In ASP.NET MVC 3 application I use Ajax.BeginForm to post writed text to controller.
@using (Ajax.BeginForm(\"Post\", \"Forum\", new {threadId = Model.Thread
Make sure you have included the following script to your page:
and that you have enabled unobtrusive javascript in your web.config:
This is what makes Ajax.* helpers such as Ajax.BeginForm to work.
Ajax.*
Ajax.BeginForm