I can't seem to access or set session variables in my app... everything's null. I've tried both Session["var"] and HttpContext.Current.Session["var"] and get a NullReferenceException every time.

am I missing something? Do I have to check each and every variable to see if it's null before I try to use it?

In Session_OnStart eventHander declair all session variable with default value.

Bijgupt

Hmm.. did not think about that.

I ended up solving it by *casting* each session variable to a string, instead of .ToString()ing the session variables.

You cannot ToString() a null object, but you can cast it to a string.

Hi
I have the same problem and casting it to string is not helping either. I am trying to debug the application and i have defines Session variable in Global.asax file but the control doesnt go there.
Here is my Global.asax code
 void httpmodule_SessionHandler(Object sender, EventArgs e)
    {
        /// <summary>
        ///Instance of cGlobal class witch will manage every request to web server
        /// </summary>
       Conversion _session = new Conversion();
    }
    void Application_Start(object sender, EventArgs e)
    {
        // Code that runs on application startup
        //Conversion _session = new Conversion();

    }

      void Session_Start(object sender, EventArgs e)
    {
        // Code that runs when a new session is started
        Conversion _session = new Conversion();
        Session["Started"] = true;

    }

Conversion is another class file where i am trying to get the value of session variable and getting NullRefernceException Error.
Here is code for that class:

public class Conversion
{
    string strServerName;
    string logonid;
    Database db = null;
    HttpContext _http = HttpContext.Current;

   string _connString = ConfigurationSettings.AppSettings["connString"];

    public Conversion()
    {

            //get the environment and data connection string
            strServerName = HttpContext.Current.Request.ServerVariables["SERVER_NAME"];
            strServerName = strServerName.ToString().Trim().ToUpper();
         if ((String)HttpContext.Current.Session["Started"]==null )
            {
                switch (strServerName)
                {
                                    }

   Any help will be appreciated.

Thanks
Kamal