Safari problem with check boxes

Safari question.....why won't the "District - Subdistrict" menus work for me? When I click the icon I get a separate smaller window opening, but the district listing (which has check boxes) doesn't show. It's fine from my Internet Explorer from the PC, but my iMac with Safari won't do it. Here's the link if you wouldn't mind lending a newbie a hand. Many thanks.....

http://sfarmls.rapmls.com/scripts/m...GNAME=MLSLogin&ARGUMENT=e0NTnO+xzb4=&KeyRid=0