diff --git a/lib/filelib.php b/lib/filelib.php
index 37806b97542..a41c57615f3 100644
--- a/lib/filelib.php
+++ b/lib/filelib.php
@@ -566,7 +566,7 @@ function file_get_draft_area_files($draftitemid, $filepath = '/') {
 
             $icon = mimeinfo_from_type('icon', $file->get_mimetype());
             $icon = str_replace('.gif', '', $icon);
-            $item->icon = $OUTPUT->pix_url('f/' . $icon);
+            $item->icon = $OUTPUT->pix_url('f/' . $icon)->out();
 
             if ($icon == 'zip') {
                 $item->type = 'zip';
@@ -576,7 +576,7 @@ function file_get_draft_area_files($draftitemid, $filepath = '/') {
 
             if ($file->is_directory()) {
                 $item->filesize = 0;
-                $item->icon = $OUTPUT->pix_url('f/folder');
+                $item->icon = $OUTPUT->pix_url('f/folder')->out();
                 $item->type = 'folder';
                 $foldername = explode('/', trim($item->filepath, '/'));
                 $item->fullname = trim(array_pop($foldername), '/');
diff --git a/lib/javascript-static.js b/lib/javascript-static.js
index d7233affa25..9ef86076688 100644
--- a/lib/javascript-static.js
+++ b/lib/javascript-static.js
@@ -5,8 +5,17 @@
 var Y = null;
 
 // Global M object, this helps with solving of namespace and scope issues
-var M = {};
+var M = M || {};
 
+function launch_filemanager(options) {
+    Y.use('core_filemanager', function() {
+            var client_id = options.client_id;
+            // filemangers defined in lib/form/filemanager.js
+            if (!filemanagers[client_id]) {
+                filemanagers[client_id] = new M.core_filemanager(options);
+            }
+    });
+}
 
 // === old legacy JS code, hopefully to be replaced soon by M.xx.yy and YUI3 code ===
 
@@ -1206,21 +1215,11 @@ function stripHTML(str) {
 }
 
 function json_decode(json) {
-    try {
-        var obj = YAHOO.lang.JSON.parse(json);
-    } catch (e) {
-        alert(e.toString() + "\n" + stripHTML(json));
-    }
-    return obj;
+    return Y.JSON.parse(json);
 }
 
 function json_encode(data) {
-    try {
-        var json = YAHOO.lang.JSON.stringify(data);
-    } catch (e) {
-        alert(e.toString());
-    }
-    return json;
+    return Y.JSON.stringify(data);
 }
 
 /**
@@ -1317,8 +1316,17 @@ function confirm_dialog(event, args) {
 
         if (target.args.callback) {
             // args comes from PHP, so callback will be a string, needs to be evaluated by JS
-            var callback = eval('('+target.args.callback+')');
-            callback.apply(this);
+            var callback = null;
+            if (Y.Lang.isFunction(target.args.callback)) {
+                callback = target.args.callback;
+            } else {
+                callback = eval('('+target.args.callback+')');
+            }
+            if (Y.Lang.isObject(target.args.scope)) {
+                callback.apply(target.args.scope);
+            } else {
+                callback();
+            }
         }
 
         if (target.tagName.toLowerCase() == 'a') {
diff --git a/repository/lib.php b/repository/lib.php
index 5f649d3c292..db51d898cde 100644
--- a/repository/lib.php
+++ b/repository/lib.php
@@ -836,7 +836,7 @@ abstract class repository {
                     'url'=>$fileinfo->get_url(),
                     'id'=>$file->get_itemid(),
                     'file'=>$file->get_filename(),
-                    'icon' => $OUTPUT->pix_url(file_extension_icon($thefile, 32))
+                    'icon' => $OUTPUT->pix_url(file_extension_icon($thefile, 32))->out()
                 );
             } else {
                 return null;