Index: /lang/javascript/userscripts/autofocus.user.js
===================================================================
--- /lang/javascript/userscripts/autofocus.user.js (revision 4500)
+++ /lang/javascript/userscripts/autofocus.user.js (revision 7505)
@@ -143,5 +143,5 @@
 
 function createHTMLDocumentByString(str) {
-    var html = str.replace(/<!DOCTYPE.*?>/, '').replace(/<html.*?>/, '').replace(/<\/html>.*/, '');
+    var html = str.replace(/<!DOCTYPE\s[^>]*?>|<html[^>]*?>|<\/html\s*>.*/g, '');
     var htmlDoc  = document.implementation.createDocument(null, 'html', null);
     var fragment = createDocumentFragmentByString(html);