add: if (!Event.isLeftClick(evt)) return; 
context:     zoomBarDown:function(evt) {        this.map.events.register("mousemove", this, this.passEventToSlider);        this.map.events.register("mouseup", this, this.passEventToSlider);        this.mouseDragStart = evt.xy.copyOf();        this.zoomStart = evt.xy.copyOf();        this.div.style.cursor = "move";        Event.stop(evt);    },
meta: 8310	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8310/c92cd6d88a59f79879c73965c26269e13afa25e3/PanZoomBar.js/clean/lib/OpenLayers/Control/PanZoomBar.js