add getLayer() function to Map

git-svn-id: http://svn.openlayers.org/trunk/openlayers@979 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Map.js

@@ -233,6 +233,24 @@ OpenLayers.Map.prototype = {
   /*                                                      */
   /********************************************************/         
 
+    /**
+     * @param {String} name
+     * 
+     * @returns The Layer with the corresponding id from the map's 
+     *           layer collection, or null if not found.
+     * @type OpenLayers.Layer
+     */
+    getLayer: function(id) {
+        var foundLayer = null;
+        for (var i = 0; i < this.layers.length; i++) {
+            var layer = this.layers[i];
+            if (layer.id == id) {
+                foundLayer = layer;
+            }
+        }
+        return foundLayer;
+    },
+
     /**
     * @param {OpenLayers.Layer} layer
     */