start with the patch from OL Trac ticket 2133

lib/OpenLayers/Protocol/CSW.js

@@ -0,0 +1,32 @@
+/* Copyright (c) 2006-2008 MetaCarta, Inc., published under the Clear BSD
+ * license.  See http://svn.openlayers.org/trunk/openlayers/license.txt for the
+ * full text of the license. */
+
+/**
+ * @requires OpenLayers/Protocol.js
+ */
+
+/**
+ * Class: OpenLayers.Protocol.CSW
+ * Used to create a versioned CSW protocol.  Default version is 2.0.2.
+ *
+ * Inherits from:
+ *  - <OpenLayers.Protocol>
+ */
+OpenLayers.Protocol.CSW = function(options) {
+    options = OpenLayers.Util.applyDefaults(
+        options, OpenLayers.Protocol.CSW.DEFAULTS
+    );
+    var cls = OpenLayers.Protocol.CSW["v"+options.version.replace(/\./g, "_")];
+    if(!cls) {
+        throw "Unsupported CSW version: " + options.version;
+    }
+    return new cls(options);
+};
+
+/**
+ * Constant: OpenLayers.Protocol.CSW.DEFAULTS
+ */
+OpenLayers.Protocol.CSW.DEFAULTS = {
+    "version": "2.0.2"
+};