diff --git a/tail.sub.php b/tail.sub.php
index 09984cf87..219af7ba2 100644
--- a/tail.sub.php
+++ b/tail.sub.php
@@ -14,7 +14,7 @@ $(function() {
     $td_name.each(function() {
         $(this).css("z-index", count);
         $(this).css("position", "relative");
-        count--;
+        count = count - 1;
     });
 });
 </script>