>>>>It's Linq. Think it came in .NET 3.5 ?
>>>>Even simpler, BTW :

bool isWithin = cstring.Split(',').Contains(iNumber.ToString());

>>>
>>>Again, thank you very much. As I just mentioned to Gregory, I can't seem to see the Contains in my list of methods (in Intellisense).
>>
>>You need to add LINQ reference to the using statement. Try pressing ctrl+dot after you typed Contains and see if it suggests you the using statement.
>
>Is LINQ available in .NET 2.0?

Not sure, I think it's 3.0 or 3.5 Can you do a quick google search?