diff --git a/kallithea/public/js/base.js b/kallithea/public/js/base.js
--- a/kallithea/public/js/base.js
+++ b/kallithea/public/js/base.js
@@ -697,7 +697,7 @@ function _comment_div_append_form($comme
             if (!confirm('Confirm to delete this pull request')) {
                 return false;
             }
-            var comments = $('.comment').size();
+            var comments = $('.comment').length;
             if (comments > 0 &&
                 !confirm('Confirm again to delete this pull request with {0} comments'.format(comments))) {
                 return false;
diff --git a/kallithea/templates/changeset/changeset_file_comment.html b/kallithea/templates/changeset/changeset_file_comment.html
--- a/kallithea/templates/changeset/changeset_file_comment.html
+++ b/kallithea/templates/changeset/changeset_file_comment.html
@@ -198,7 +198,7 @@ $(document).ready(function () {
 
    $(window).on('beforeunload', function(){
       var $textareas = $('.comment-inline-form textarea[name=text]');
-      if($textareas.size() > 1 ||
+      if($textareas.length > 1 ||
          $textareas.val()) {
          // this message will not be displayed on all browsers
          // (e.g. some versions of Firefox), but the user will still be warned