Improve Control.KeyboardDefaults. Fixes #42.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@2540 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/KeyboardDefaults.js

@@ -28,7 +28,7 @@ OpenLayers.Control.KeyboardDefaults.prototype =
     draw: function() {
         OpenLayers.Event.observe(document, 
                       'keypress', 
-                      this.defaultKeyDown.bind(this));
+                      this.defaultKeyDown.bindAsEventListener(this));
     },
     
     /**
@@ -48,6 +48,20 @@ OpenLayers.Control.KeyboardDefaults.prototype =
             case OpenLayers.Event.KEY_DOWN:
                 this.map.pan(0, 50);
                 break;
+            case 33: // Page Up 
+                this.map.zoomIn();
+                break;
+            case 34: // Page Down 
+                this.map.zoomOut();
+                break;
+        }
+        switch(evt.charCode) {
+            case 43: // +
+                this.map.zoomIn();
+                break;
+            case 45: // -
+                this.map.zoomOut();
+                break;
         }        
     },