Get session object from sessionID in ASP.Net

Is there anyway to get a session object from a sessionID?

I have a small project using a Flash upload to let a user upload their file to the server, but the problem is that Flash has some error when sending the session and cookie (in Firefox or C开发者_StackOverflow中文版hrome, but not IE), so I found a solution to fix this problem: sending the sessionID through Flash to the server, and on the server, decode sessionID back to the session object, but I don't how to do it. I'm using ASP.NET and C#.

Can anyone advise me on what to do?

The link proposed by Moo-Juice is no longer working.

I used the code provided in this page:

http://snipplr.com/view/15180/

It worked like a charm.

If the link would become broken, here is the code:

void Application_BeginRequest(object sender, EventArgs e)
{
    try
    {
        string session_param_name = "ASPSESSID";
        string session_cookie_name = "ASP.NET_SESSIONID";
        string session_value = Request.Form[session_param_name] ?? Request.QueryString[session_param_name];
        if (session_value != null) { UpdateCookie(session_cookie_name, session_value); }
    }
    catch (Exception) { }

    try
    {
        string auth_param_name = "AUTHID";
        string auth_cookie_name = FormsAuthentication.FormsCookieName;
        string auth_value = Request.Form[auth_param_name] ?? Request.QueryString[auth_param_name];

        if (auth_value != null) { UpdateCookie(auth_cookie_name, auth_value); }
    }
    catch (Exception) { }
}
void UpdateCookie(string cookie_name, string cookie_value)
{
    HttpCookie cookie = HttpContext.Current.Request.Cookies.Get(cookie_name);
    if (cookie == null)
    {
        HttpCookie cookie1 = new HttpCookie(cookie_name, cookie_value);
        Response.Cookies.Add(cookie1);
    }
    else
    {
        cookie.Value = cookie_value;
        HttpContext.Current.Request.Cookies.Set(cookie);
    }
}