How do I check if an object has been created?

loOutlook = CREATEOBJECT("Outlook.Application")

*Get the MAPI namespace and find the contacts folder
loNamespace = loOutlook.GetNameSpace("MAPI")
loFolder = loNameSpace.PickFolder

The Pickfolder allows for the selection of a folder in Outlook, but if the user presses cancel, loFolder doesn't become an object, so i want to check if loFolder has been created before doing anything else.