How Do I Pass Values From Javascript To My Mvc Controller ?

I tried the above msdn link. But still it is loading my page onclick of submit button.
View:

@Html.Encode(ViewData["Message"])

<p>
Page Rendered: @DateTime.Now.ToLongTimeString()
</p>
<span id="status">No Status</span>
<br />
@Ajax.ActionLink("Update Status", "GetStatus", new AjaxOptions{UpdateTargetId="status" })
<br /><br />
@using(Ajax.BeginForm("UpdateForm", new AjaxOptions{UpdateTargetId="textEntered"})) {
@Html.TextBox("textBox1","Enter text")
<input type="submit" value="Submit"/><br />
<span id="textEntered">Nothing Entered</span>
}


Controller:
public class HomeController : Controller
{
public ActionResult Index()
{
return View();
}

public ActionResult About()
{
return View();
}
public string GetStatus()
{
return "Status OK at " + DateTime.Now.ToLongTimeString();
}

public string UpdateForm(string textBox1)
{
if (textBox1 != "Enter text")
{
return "You entered: \"" + textBox1.ToString() + "\" at " +
DateTime.Now.ToLongTimeString();
}

return String.Empty;
}
}

On click of submit it is loading the entire page.I want to load only that part asynchronously.

Many Thanks