diff --git a/docs/bookdown/libs/kePrint-0.0.1/kePrint.js b/docs/bookdown/libs/kePrint-0.0.1/kePrint.js
index 4f9728d..e6fbbfc 100644
--- a/docs/bookdown/libs/kePrint-0.0.1/kePrint.js
+++ b/docs/bookdown/libs/kePrint-0.0.1/kePrint.js
@@ -1,4 +1,8 @@
 $(document).ready(function(){
-    $('[data-toggle="tooltip"]').tooltip();
-    $('[data-toggle="popover"]').popover();
+    if (typeof $('[data-toggle="tooltip"]').tooltip === 'function') {
+        $('[data-toggle="tooltip"]').tooltip();
+    }
+    if ($('[data-toggle="popover"]').popover === 'function') {
+        $('[data-toggle="popover"]').popover();
+    }
 });