Return error message if username is already taken during register

This will return an error message if the username is already registered. The user should choose another name

frontend/src/components/Input.css

@@ -38,4 +38,4 @@ form {
 
 .input-field label {
   font-size: 1.5em;
-}
+}

frontend/src/components/pages/Register.js

@@ -4,6 +4,7 @@ import "../../App.css";
 import Footer from "../../Footer";
 import InputField from "../InputField";
 import SubmitField from "../SubmitField";
+import "../Input.css"
 
 export default function Login() {
   const [username, setUsername] = useState("");
@@ -21,15 +22,17 @@ export default function Login() {
       method: "post",
       body: JSON.stringify(opts),
     }).then((response) => {
+      console.log(response)
       if (response.status === 409) {
-        console.log(response);
+        /* 
-        console.log(
+        then is needed twice to get rid of the javascript Promise thing
-          "Benutzername wird bereits verwendet. Wähle einen Anderen (source: console.log)"
+        */
-        );
+        response.json().then((resp2) => {
-        let response_json = response.json();
+          setMessage(resp2.message)
-        console.log(response_json);
+        });
-        let response_message = response_json.message;
+      }
-        console.log(response_message);
+      else if (response.status === 200) {
+        //TODO  redirect to login #77 or #74
       }
     });
   };
@@ -53,6 +56,7 @@ export default function Login() {
             onChange={handleUsernameChange}
             InputName="username"
           />
+          <p>{message}</p>
           <InputField
             LabelName="Passwort"
             InputType="password"