// requires jQuery
var lastul;
$(document).ready(function(){
  lastul = $("#photo-galleries-nav > ul > li > a")
             .siblings(".photo-galleries-subnav.active");
  lastul.data("open", true);
  $("#photo-galleries-nav > ul > li > a").click(function() {
    var newul = $(this).siblings(".photo-galleries-subnav");
    if(newul.data("open") != true) {
      lastul.fadeOut(300, function() {
        newul.fadeIn();
        newul.data("open", true);
      });
      lastul.data("open", false);
    }
    lastul = newul;
  });
});