Problem deleting attributes

I have a list of attributes that I need to keep, but want to delete all others. I am able to do this with just one attribute name, but when I try to do an "or" statement it deletes all attributes. Can anyone help tell me what I am doing wrong? Code attached.
lnorton - Thu Jun 25 12:49:34 EDT 2009

Re: Problem deleting attributes
IBM_Gust - Thu Jun 25 13:10:55 EDT 2009

The double not got you -- if you study logic you might remember that when you have two knots you change either or/and.

Re: Problem deleting attributes
lnorton - Thu Jun 25 13:30:13 EDT 2009

IBM_Gust - Thu Jun 25 13:10:55 EDT 2009
The double not got you -- if you study logic you might remember that when you have two knots you change either or/and.

Thanks! Yes, it was "and" not "or"...stupid mistake on my part.