diff --git a/index.html b/index.html
index ede1d29..fb05c5c 100644
--- a/index.html
+++ b/index.html
@@ -7,7 +7,7 @@
     <table width="100%">
       <tr>
       <td width="15%">
-        <a href="javascript:changePDF('chapter 1')">Chapter 1</a><br>
+        <a href="javascript:changePDF('chapter1')">Chapter 1</a><br>
         <a href="javascript:changePDF('chapter 2')">Chapter 2</a><br>
         <a href="javascript:changePDF('chapter 3')">Chapter 3</a><br>
         <a href="javascript:changePDF('chapter 4')">Chapter 4</a><br>