Wraping Session to Gobal Session Class

using System;
using System.Web;

namespace MyApp
{
public class SessionGlobal
{

private const string _AccountNo = "_AccountNo";

// Set to default Values
public static void Clear()
{

 HttpContext.Current.Session[_AccountNo]="";

}

private static string getSessionVar(string key)
{
 if(HttpContext.Current.Session[key]!=null)
  return HttpContext.Current.
          Session[key].ToString();
 else
  return "";

}

public static string AccountNo
{
 get
 {
  return getSessionVar(_AccountNo);
 }
 set
 {
  HttpContext.Current.Session[_AccountNo]=value;
 }
}

public static string UserID
{
 get
 {
  return HttpContext.Current.
          Request.ServerVariables["AUTH_USER"];
 }

}

}
}