docs: function(centered) {
          var imgLocation = OpenLayers.Util.getImageLocation("slider.png");
          var id = this.id + "_" + this.map.id;
          var minZoom = this.map.getMinZoom();
          var zoomsToEnd = this.map.getNumZoomLevels() - 1 - this.map.getZoom();
          var slider = OpenLayers.Util.createAlphaImageDiv(id,
                         centered.add(-1, zoomsToEnd * this.zoomStopHeight), 
                         {w: 20, h: 9},
                         imgLocation,
                         "absolute");
          slider.style.cursor = "move";
          this.slider = slider;
          
          this.sliderEvents = new OpenLayers.Events(this, slider, null, true,
                                              {includeXY: true});
          this.sliderEvents.on({
              "touchstart": this.zoomBarDown,
              "touchmove": this.zoomBarDrag,
              "touchend": this.zoomBarUp,
              "mousedown": this.zoomBarDown,
              "mousemove": this.zoomBarDrag,
              "mouseup": this.zoomBarUp
          });
          
          var sz = {
              w: this.zoomStopWidth,
              h: this.zoomStopHeight * (this.map.getNumZoomLevels() - minZoom)
          };
          var imgLocation = OpenLayers.Util.getImageLocation("zoombar.png");
          var div = null;
          
          if (OpenLayers.Util.alphaHack()) {
              var id = this.id + "_" + this.map.id;
              div = OpenLayers.Util.createAlphaImageDiv(id, centered,
                                        {w: sz.w, h: this.zoomStopHeight},
                                        imgLocation,
                                        "absolute", null, "crop");
              div.style.height = sz.h + "px";
          } else {
              div = OpenLayers.Util.createDiv(
                          'OpenLayers_Control_PanZoomBar_Zoombar' + this.map.id,
                          centered,
                          sz,
                          imgLocation);
          }
          div.style.cursor = "pointer";
          div.className = "olButton";
          this.zoombarDiv = div;
          
          this.div.appendChild(div);
  
          this.startTop = parseInt(div.style.top);
          this.div.appendChild(slider);
  
          this.map.events.register("zoomend", this, this.moveZoomBar);
  
          centered = centered.add(0, 
              this.zoomStopHeight * (this.map.getNumZoomLevels() - minZoom));
          return centered; 
      }