<HttpPost()> doesn't work in my view page - asp.net-mvc

Question

I have two links say for eg. English and Spanish. When user clicks on english link it should set language to "English" in session.
The following is my aspx code
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<script type="text/javascript">
function SetLanguageSpanish() {
document.getElementById("Home_Language").value = 'Spanish';
document.getElementById("frmHome").submit();
}
function SetLanguageEnglish() {
/*var obj = document.getElementById("LangEnglish");*/
// <% Session("Language") = "English"%>;
document.getElementById("Home_Language").value = 'English';
document.getElementById("frmHome").submit();
}
</script>
<div class="vmenu">
<form id="frmHome" action="Home" method="post"">
<a id="LangEnglish" href="/" onclick="SetLanguageEnglish();" >English</a>
<a id="LangSpanish" href="/" onclick="SetLanguageSpanish();"> Spanish</a>
<h3><%= Html.Label(Model.SubTitle) %></h3>
<ul class="sbe">
<li class="sbe"><%= Model.Menu1%></li>
<li class="sbe"><%= Model.Menu2%></li>
<li class="sbe"><%= Model.Menu3%></li>
<li class="sbe"><%= Model.Menu4%></li>
<li class="sbe"><%= Model.Menu5%></li>
</ul>
<input id="Home_PageName" name="PageName" type="hidden" value="" />
<input id="Home_Language" name="Language" type="hidden" value="" />
<input id="Home_PageTitle" name="PageTitle" type="hidden" value="" />
<input id="Home_SubTitle" name="SubTitle" type="hidden" value="" />
<input id="Home_Menu1" name="Menu1" type="hidden" value="" />
<input id="Home_Menu2" name="Menu2" type="hidden" value="" />
<input id="Home_Menu3" name="Menu3" type="hidden" value="" />
<input id="Home_Menu4" name="Menu4" type="hidden" value="" />
<input id="Home_Menu5" name="Menu5" type="hidden" value="" />
</form>
</div>
</asp:Content>
and my controller class code is as follow:
Public Class HomeController
Inherits System.Web.Mvc.Controller
' GET: /Home
<OutputCache(Duration:=1800, VaryByParam:="none")>
Function Index() As ActionResult
Try
Dim oHome As New Home.Home
Dim oHomeModel As New Home.HomeVM
If (HttpContext.Session("Language") Is Nothing) Then
HttpContext.Session("Language") = "English"
End If
oHomeModel.Language = HttpContext.Session("Language").ToString()
Return View("Index", GetCaption(oHomeModel))
Catch ex As Exception
Return Nothing
End Try
End Function
<HttpPost()>
<OutputCache(Duration:=1800)>
Function Index(ByVal oHomeModel As Home.HomeVM) As ActionResult
Try
If ((oHomeModel.Language IsNot Nothing) Or (oHomeModel.Language.ToString() <> "")) Then
HttpContext.Session("Language") = oHomeModel.Language.ToString()
End If
Return View("Index", GetCaption(oHomeModel))
Catch ex As Exception
Return Nothing
End Try
End Function
For some reason when i click on any link on my view page. The Controller class get is getting fired. due to this the value in session is not getting refreshed. Can anyone suggest why this is happening?
The following is my model class.
Namespace Home
Public Class HomeVM
'The following property are used as parameter
Public Property PageName As String
Public Property Language As String
'The following are the form caption peroperty
Public Property PageTitle As String
Public Property SubTitle As String
Public Property Menu1 As String
Public Property Menu2 As String
Public Property Menu3 As String
Public Property Menu4 As String
Public Property Menu5 As String
End Class

Answer 1

It looks to me like you are mixing up server side and client side code.
<% Session("Language") = "English"%>;
The above line you have in JavaScript gets executed when the page first loads which prints nothing to the page. If you look at the source you should see nothing other than the semi-colon ;.
When you click the link that calls SetLanguageSpanish() there is nothing to be executed in that function and the page is directed to '/'. Have a look at the page source.
Edit
Here is some updated code which will submit a hidden input with the id "language" and a value of the specified by the function parameter.
HTML
<form id="frmHome" method="post">
English
Spanish
<input type="hidden" id="language" name="language" value="" />
</form>
JavaScript
function SetLanguage(language) {
document.getElementById("language").value = language;
document.getElementById("frmHome").submit();
}
VB.NET I am not a VB guy so double check the syntax here
<HttpPost()>
<OutputCache(Duration:=1800)>
Function Index(ByVal language As string) As ActionResult
HttpContext.Session("Language") = language
'Do stuff
Return this.View()
End Function