add: if (!Event.isLeftClick(evt)) return; 
context:     buttonDown: function (evt) {        var slide = this.map.getResolution() * this.slideFactor;        var center = this.map.getCenter();        var newCenter = center.copyOf();        switch (this.action) {            case "panup":                 newCenter = newCenter.add( 0, slide);                break;            case "pandown":                 newCenter = newCenter.add( 0, -slide);                break;            case "panleft":                 newCenter = newCenter.add( -slide, 0);                break;            case "panright":                 newCenter = newCenter.add( slide, 0);                break;            case "zoomin":                 this.map.zoomIn();                 break;            case "zoomout":                 this.map.zoomOut();                 break;            case "zoomworld":                 this.map.zoomToFullExtent();                 break;        }                if (!newCenter.equals(center)) {            this.map.setCenter(newCenter);        }                Event.stop(evt);    },
meta: 8310	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8310/c92cd6d88a59f79879c73965c26269e13afa25e3/PanZoom.js/buggy/lib/OpenLayers/Control/PanZoom.js