add: switch(evt.charCode) { case 43: this.map.zoomIn(); break; case 45: this.map.zoomOut(); break; } 
context:     defaultKeyDown: function (evt) {        switch(evt.keyCode) {            case OpenLayers.Event.KEY_LEFT:                this.map.pan(-50, 0);                break;            case OpenLayers.Event.KEY_RIGHT:                 this.map.pan(50, 0);                break;            case OpenLayers.Event.KEY_UP:                this.map.pan(0, -50);                break;            case OpenLayers.Event.KEY_DOWN:                this.map.pan(0, 50);                break;        }    },
meta: 1027	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/1027/be1ef0ef47d5c1df6d5b2cc6932076cb6ea90073/KeyboardDefaults.js/buggy/lib/OpenLayers/Control/KeyboardDefaults.js