Session Time out very early

Question

Dear all I have an application is hosted and  its session is time out very early weather I  have given much time in web.config below is the code of web.config

<system.web>

<sessionState

      mode="InProc"

      timeout="120" />

    <customErrors mode="Off"/>

    <compilation debug="true" targetFramework="4.0">
And below is the code of my logout page

 Session.Clear()

        Session.Abandon()

        LoggedInUserId = 0

        Response.Cache.SetCacheability(HttpCacheability.NoCache)

        Response.Cache.SetExpires(DateTime.Now.AddMinutes(60))

        Response.Cache.SetNoStore()

        Response.Redirect("~/Login.aspx")