coyote: CGOBJ_ISA

Description
The purpose of this utility routine is to check to be sure the object argument is 
valid and belongs to the specified object class. It is more useful than the built-in
Obj_Isa function, because it can handle undefined variable arguments.
Categories
Utilities
Returns
The function returns a 0 to indicate FALSE or a 1 to indicate TRUE. If passed
an array of objects, it will return an array of 0s and 1s for each object.
Params
object: in, optional, type=object
   The object reference to check. It may be undefined. This variable may
   also be an array.
classname: in, optional, type=string
   The object class name. If undefined, the function always returns false.   
Examples
Here is how to use this program::
   IDL> IF cgObj_ISA(object, 'cgKML_Feature') THEN object -> SetProperty, PLACENAME='Boulder'
Author
FANNING SOFTWARE CONSULTING::
   David W. Fanning 
   1645 Sheely Drive
   Fort Collins, CO 80526 USA
   Phone: 970-221-0438
   E-mail: david@idlcoyote.com
   Coyote's Guide to IDL Programming: http://www.idlcoyote.com
History
Change History::
   Written, 4 Novemeber 2012 by David W. Fanning.
Copyright
Copyright (c) 2012, Fanning Software Consulting, Inc.