code: function plotclick(event, pos, item) {
              if (! that.clickmode) {
                  // it is the click activating the clicktip
                  plothover(event, pos, item);
                  if (that.getDomElement().is(":visible")) {
                      $(plot.getPlaceholder()).unbind("plothover", plothover);
                      that.clickmode = true;
                  }
              } else {
                  // it is the click deactivating the clicktip
                  $( plot.getPlaceholder() ).bind("plothover", plothover);
                  plot.hideTooltip();
                  that.clickmode = false;
              }
          }
docs: open the tooltip (if not already open) and freeze it on the current position till the next click