docs: function (target) {
              var elem = $(target);
              var maxValue = 0;
              var position, value;
              while (elem.length && elem[0] !== document) {
                  position = elem.css("position");
                  if (position === "absolute" || position === "relative" || position === "fixed") {
                      value = parseInt(elem.css("zIndex"), 10);
                      if (!isNaN(value) && value !== 0) {
                          if (value > maxValue) { maxValue = value; }
                      }
                  }
                  elem = elem.parent();
              }
  
              return maxValue;
          }