When I travel to the Holiday Inn in Aruba I usually send them an e-mail through/to
http://caribbeanhi.com/aruba/index.p..._id=1&Itemid=3 and/or
HIAruba@ihg.com to make the request (I send it both ways to make sure that the hotel receives my request). I would send your request to them one week before you arrive (that is what they have told me to do when I have e-mailed them in the past).
