Flush existing classes
diff --git a/js/build_page.js b/js/build_page.js
index 7aa08da..3b2745f 100644
--- a/js/build_page.js
+++ b/js/build_page.js
@@ -113,6 +113,11 @@
     var duplicateSubjectBoolNext, duplicateSubjectBoolPrev;

     var duplicateSubjectCounter = 0;

     

+    // Flush existing classes

+    document.querySelectorAll('.message').forEach(function(classe) {

+        classe.classList.add('is-hidden');

+    });

+    

     for (var [i, classe] of classes.entries()) {        

         var hora_inici = formatDate(new Date(parseInt(classe.begins)*1000));

         var hora_final = formatDate(new Date(parseInt(classe.ends)*1000));