diff --git a/tabeleditor.inc.php b/tabeleditor.inc.php
index afb1b79..8f3d5bf 100644
--- a/tabeleditor.inc.php
+++ b/tabeleditor.inc.php
@@ -126,11 +126,13 @@
   function __vertical_center(elm) {
     var ruler = document.querySelector("#ruler");
 
+    ruler.style.display = "block";
     ruler.innerText = elm.value;
     if (ruler.innerText == "" || ruler.innerText.endsWith("\\n")) { ruler.innerText += "."; }
     var pad= ((ruler.orig_height - ruler.offsetHeight)/2);
     elm.style.paddingTop = pad + "px";
     elm.style.height = (ruler.orig_height - pad) + "px";
+    ruler.style.display = "none";
   }
 
   function change_handler(e) {