Fix click-to-zoom.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@373 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/PanZoomBar.js

@@ -91,7 +91,7 @@ OpenLayers.Control.PanZoomBar.prototype =
     },
     divClick: function (evt) {
         var y = evt.xy.y;
-        var top = parseInt(this.slider.top);
+        var top = Position.page(evt.object)[1];
         var levels = Math.floor((y - top)/this.zoomStopHeight);
         this.map.zoomTo(this.map.getZoomLevels() - levels);
         Event.stop(evt);