diff --git a/app/assets/mixed/summernote-0.8.18-dist/summernote-lite.js b/app/assets/mixed/summernote-0.8.18-dist/summernote-lite.js
index 8e50990..f4de057 100644
--- a/app/assets/mixed/summernote-0.8.18-dist/summernote-lite.js
+++ b/app/assets/mixed/summernote-0.8.18-dist/summernote-lite.js
@@ -5856,7 +5856,9 @@ var Editor_Editor = /*#__PURE__*/function () {
     value: function beforeCommand() {
       this.context.triggerEvent('before.command', this.$editable.html()); // Set styleWithCSS before run a command
 
-      document.execCommand('styleWithCSS', false, this.options.styleWithCSS); // keep focus on editable before command execution
+      try {
+        document.execCommand('styleWithCSS', false, this.options.styleWithCSS); // keep focus on editable before command execution
+      } catch (e) {}
 
       this.focus();
     }
diff --git a/app/index.js b/app/index.js
index 9f92da5..92c3596 100644
--- a/app/index.js
+++ b/app/index.js
@@ -79,29 +79,29 @@ Router.add('/test', function(render) {
 // nodepad
 Router.add('/notepad', function(render) {
     // load resources
-    Browser.addResources([
-        {
-            type: "javascript",
-            url: "app/assets/mixed/summernote-0.8.18-dist/summernote-lite.js"
-        },
-        {
-            type: "stylesheet",
-            url: "app/assets/mixed/summernote-0.8.18-dist/summernote-lite.css"
-        }
-    ]);
+    Browser.addStylesheet("app/assets/mixed/summernote-0.8.18-dist/summernote-lite.css");
+    Browser.waitUntil(function(test, ttl) {
+        Browser.addScript("app/assets/mixed/summernote-0.8.18-dist/summernote-lite.js", function(el) {
+            // set DOM id
+            var target_dom_id = "summernote";
 
-    // set DOM id
-    var target_dom_id = "summernote";
+            // load HTML
+            render("app/notepad.html", {
+                "target_dom_id": target_dom_id
+            });
 
-    // load HTML
-    render("app/notepad.html", {
-        "target_dom_id": target_dom_id
+            // load Summernote (wysiwyg editor)
+            $('#' + target_dom_id).summernote({
+                minHeight: 300
+            });
+
+        }, test, ttl);
+    }, function(el) {
+        alert(typeof $.summernote);
+        return $.summernote;
     });
 
-    // load Summernote (wysiwyg editor)
-    $('#' + target_dom_id).summernote({
-        minHeight: 300
-    });
+	document.getElementById("useragent").innerHTML = window.navigator.userAgent;
 });
 
 // go
diff --git a/app/notepad.html b/app/notepad.html
index 118a3ed..b00a97f 100644
--- a/app/notepad.html
+++ b/app/notepad.html
@@ -8,5 +8,18 @@
                 </div>
             </div>
         </div>
+
+        <div class="col">
+            <div class="panel cell">
+                <div class="header">User Agent</div>
+                <div class="body">
+                    <div class="cell">
+                        <div class="col">
+                            <span id="useragent"></span>
+                        </div>
+                    </div>
+                </div>
+            </div>
+        </div>
     </div>
 </div>
diff --git a/lib/browser.js b/lib/browser.js
index cb8447c..4b0b111 100644
--- a/lib/browser.js
+++ b/lib/browser.js
@@ -128,7 +128,7 @@ function getIEVersion() {
 };
 
 ////////////////////////////////////////////////////////////////////////
-// exports.waitUntil()
+// waitUntil()
 ////////////////////////////////////////////////////////////////////////
 function waitUntil(f, test, ttl) {
     if (typeof f !== "function") return;
@@ -177,34 +177,26 @@ function addScript(url, callback, test, ttl) {
     return el;
 };
 
-////////////////////////////////////////////////////////////////////////
-// addResources()
-////////////////////////////////////////////////////////////////////////
-function addResources(resources, callback) {
-    resources.forEach(function(resource) {
-        if (["javascript", "text/javascript"].indexOf(resource.type) > -1) {
-            addScript(resource.url, callback);
-        } else if (["stylesheet", "text/css"].indexOf(resource.type) > -1) {
-            addStylesheet(resource.url, callback);
-        } else {
-            console.warn("Not supported resource type");
-        }
-    });
-};
-
 ////////////////////////////////////////////////////////////////////////
 // addStylesheet()
 ////////////////////////////////////////////////////////////////////////
-function addStylesheet(url, callback) {
+function addStylesheet(url, callback, test, ttl) {
+    if (typeof test !== "function") {
+        test = function(el, callback, ttl) {};
+    }
+    var ttl = (typeof ttl === "number" ? ttl : 30000);  // TTL(Time-To-Live)
+
     var el = document.createElement("link");
     el.href = url;
     el.rel = "stylesheet";
     el.type = "text/css";
     el.media = "screen, projection";
     document.head.appendChild(el);
-    if (typeof(callback) === "function") {
-        el.onload = callback(el);
+
+    if (typeof test === "function") {
+        test(el, callback, ttl);
     }
+
     return el;
 };
 
@@ -274,14 +266,13 @@ function close() {
 exports.getIEVersion = getIEVersion;
 exports.waitUntil = waitUntil;
 exports.addScript = addScript;
-exports.addResources = addResources;
 exports.addStylesheet = addStylesheet;
 exports.setContent = setContent;
 exports.start = start;
 exports.reload = reload;
 exports.close = close;
 
-exports.VERSIONINFO = "Browser Library (browser.js) version 0.1.3";
+exports.VERSIONINFO = "Browser Library (browser.js) version 0.1.4";
 exports.AUTHOR = "abuse@catswords.net";
 exports.global = global;
 exports.require = global.require;