1 files changed, 21 insertions, 5 deletions
diff --git a/src/navtree.js b/src/navtree.js
index 4fb2c87..5549d7f 100644
--- a/src/navtree.js
+++ b/src/navtree.js
@@ -22,9 +22,15 @@ function stripPath2(uri)
 
 function localStorageSupported()
 {
-  return 'localStorage' in window && window['localStorage'] !== null;
+  try {
+    return 'localStorage' in window && window['localStorage'] !== null && window.localStorage.getItem;
+  }
+  catch(e) {
+    return false;
+  }
 }
 
+
 function storeLink(link)
 {
   if (!$("#nav-sync").hasClass('sync') && localStorageSupported()) {
@@ -411,16 +417,26 @@ function navTo(o,root,hash,relpath)
   }
 }
 
+function showSyncOff(n,relpath)
+{
+    n.html('<img src="'+relpath+'sync_off.png" title="'+SYNCOFFMSG+'"/>');
+}
+
+function showSyncOn(n,relpath)
+{
+    n.html('<img src="'+relpath+'sync_on.png"/ title="'+SYNCONMSG+'">');
+}
+
 function toggleSyncButton(relpath)
 {
   var navSync = $('#nav-sync');
   if (navSync.hasClass('sync')) {
     navSync.removeClass('sync');
-    navSync.html('<img src="'+relpath+'sync_off.png"/>');
+    showSyncOff(navSync,relpath);
     storeLink(stripPath2($(location).attr('pathname'))+$(location).attr('hash'));
   } else {
     navSync.addClass('sync');
-    navSync.html('<img src="'+relpath+'sync_on.png"/>');
+    showSyncOn(navSync,relpath);
     deleteLink();
   }
 }
@@ -448,10 +464,10 @@ function initNavTree(toroot,relpath)
   if (localStorageSupported()) {
     var navSync = $('#nav-sync');
     if (cachedLink()) {
-      navSync.html('<img src="'+relpath+'sync_off.png"/>');
+      showSyncOff(navSync,relpath);
       navSync.removeClass('sync');
     } else {
-      navSync.html('<img src="'+relpath+'sync_on.png"/>');
+      showSyncOn(navSync,relpath);
     }
     navSync.click(function(){ toggleSyncButton(relpath); });
   }