What is the best way to determine a session variable is null or empty in C#?

Question

What is the best way to check for the existence of a session variable in ASP.NET C#?

I like to use String.IsNullOrEmpty() works for strings and wonder

Answer 1

Are you using .NET 3.5? Create an IsNull extension method:

public static bool IsNull(this object input)
{
    input == null ? return true : return false;
}

public void Main()
{
   object x = new object();
   if(x.IsNull)
   {
      //do your thing
   }
}