How to determine if a string contains a GUID vs just a string of numbers.
will a GUID always contain at least 1 alpha character?
See if these helps :-
Guid guidResult = Guid.Parse(inputString)
(http://msdn.microsoft.com/en-us/library/system.guid.parse.aspx)
bool isValid = Guid.TryParse(inputString, out guidOutput)
http://msdn.microsoft.com/en-us/library/system.guid.tryparse.aspx