No More Session Variable Misspellings

I was recently tasked with adding a series of web pages to a huge existing site. Since I was new to the project, I wasn't privvy to all of the previously existing session variables, presenting quite the problem where naming a new Session element was concerned. First, I gave all of my new session variables a prefix so I could at least guarantee (to some extent) that they would be unique to the module I was working on. However, the list of variables became extensive, not to mention the possibility of typing a name incorrectly, thus unintentionally creating another variable. To solve this issue, I came up with the following scheme.

In a word, it involves using an enum. I simply define an enum, like so:

public enum A00SessionVars { A00Value1, A00Value2, ... and so on };

And refer to it like this in the code:

Session(A00SessionVars.A00Value1.ToString())

Yes, it made for more typing, but I never once had anything unexpected happen as a result of spelling a name wrong, and it's impossible to add two variables that are the same name (with a deft bow of the head in the direction of C#'s case-sensitivity).

EDIT ==============

I was working on the code again today, and decided that using ToString() was too clunky, so I came up with this:

// C# version
//-----------------------------------------------------------------
Public T GetSessionVar<T>(A00SessionVars item, T defaultValue)
{
    T value = defaultValue;
    Object obj = Session(item.ToString();
    if (obj == null)
    {
        SetSessionVar(item.ToString(), value);
    }
    else
    {
        value = obj as T;
    }
    return value;
}

//-----------------------------------------------------------------
Public void SetSessionVar(A00SessionVars item, Object value)
{
    Session(item.ToString()) = value;
}

'VB version
'-------------------------------------------------------------------------------------
Public Function GetSessionVar(Of T)(ByVal item As G00SessionVars, ByVal defaultValue As T) As T
    Dim value As T = defaultValue
    Dim obj As Object = Session(item.ToString())
    If (obj Is Nothing) Then
        SetSessionVar(item.ToString(), value)
    Else
        value = CType(obj, T)
    End If
    Return value
End Function

'-------------------------------------------------------------------------------------
Public Sub SetSessionVar(ByVal item As G00SessionVars, ByVal value As Object)
    Session(item.ToString()) = value
End Sub

Now I can get/set just by doing this:

// For C#
int    i = GetSessionVar(A00SessionVars.A00Value1, -1);
string s = GetSessionVar(A00SessionVars.A00Value2, "N/A");

' For VB
Dim i As Integer = GetSessionVar(A00SessionVars.A00Value1, -1)
Dim s As String  = GetSessionVar(A00SessionVars.A00Value2, "N/A")

Now, I'm going to go back and see if anyone suggested this (I haven't read any of the alternatives or comments yet).