diff --git a/1-js/11-async/03-promise-chaining/head.html b/1-js/11-async/03-promise-chaining/head.html
index 31c6b427..0a0075fb 100644
--- a/1-js/11-async/03-promise-chaining/head.html
+++ b/1-js/11-async/03-promise-chaining/head.html
@@ -10,25 +10,6 @@ function loadScript(src) {
     document.head.append(script);
   });
 }
-
-class HttpError extends Error {
-  constructor(response) {
-    super(`${response.status} for ${response.url}`);
-    this.name = 'HttpError';
-    this.response = response;
-  }
-}
-
-function loadJson(url) {
-  return fetch(url)
-    .then(response => {
-      if (response.status == 200) {
-        return response.json();
-      } else {
-        throw new HttpError(response);
-      }
-    })
-}
 </script>
 
 <style>
diff --git a/1-js/11-async/04-promise-error-handling/head.html b/1-js/11-async/04-promise-error-handling/head.html
index 31c6b427..a0b74196 100644
--- a/1-js/11-async/04-promise-error-handling/head.html
+++ b/1-js/11-async/04-promise-error-handling/head.html
@@ -1,16 +1,4 @@
 <script>
-function loadScript(src) {
-  return new Promise(function(resolve, reject) {
-    let script = document.createElement('script');
-    script.src = src;
-
-    script.onload = () => resolve(script);
-    script.onerror = () => reject(new Error("Script load error: " + src));
-
-    document.head.append(script);
-  });
-}
-
 class HttpError extends Error {
   constructor(response) {
     super(`${response.status} for ${response.url}`);