diff --git a/app/views/boards/show.html.erb b/app/views/boards/show.html.erb
index f25e690d0..589a0f25d 100644
--- a/app/views/boards/show.html.erb
+++ b/app/views/boards/show.html.erb
@@ -13,7 +13,9 @@
     var menuids=["TopUserNav"] //Enter id(s) of SuckerTree UL menus, separated by commas
     function buildsubmenus(){
         for (var i=0; i<menuids.length; i++){
-            var ultags=document.getElementById(menuids[i]).getElementsByTagName("ul")
+            var div = document.getElementById(menuids[i]);
+            if(div == undefined)continue;
+            var ultags=div.getElementsByTagName("ul")
             for (var t=0; t<ultags.length; t++){
                 ultags[t].parentNode.getElementsByTagName("a")[0].className="subfolderstyle"
                 ultags[t].parentNode.onmouseover=function(){