Use message box for error messages

assets/js/vue/components/alsijil/CourseBook.js

@@ -88,7 +88,7 @@ export default {
     >
     <template v-slot="{ result: { loading, error, data } }">
         <!-- Error -->
-        <div v-if="error" class="error apollo">An error occurred</div>
+        <message-box v-if="error" type="error">An error occurred</message-box>
     
         <!-- Result -->
         <div v-else-if="data" class="result apollo">