diff --git a/internal/js/files_support.js b/internal/js/files_support.js
index aa71da3..780c3a3 100644
--- a/internal/js/files_support.js
+++ b/internal/js/files_support.js
@@ -628,3 +628,8 @@ function prevPage()
     resetNextPrevButtons()
     return
 }
+
+function isMobile() {
+    try{ document.createEvent("TouchEvent"); return true; }
+    catch(e){ return false; }
+}