Sam's Club membership number is required. In the past I've used

1029991122545776

and it has worked fine; try making a small alteration to that # and it'll probably work.

http://www.samsclubmemberservices.com/Events/depend.aspx

SS URL:

http://www.startsampling.com/sm/100901/captureAddress.iphtml?item=100901&source=

These are the sizes available:

Mens size S/M: 28"-40" waist
Womens size S/M: 28"-40" Waist
Womens size L: 38"-50" Waist