Fix typo.
diff --git a/src/site/apt/tutorial.apt b/src/site/apt/tutorial.apt
index 6e520e5..a56d138 100644
--- a/src/site/apt/tutorial.apt
+++ b/src/site/apt/tutorial.apt
@@ -157,7 +157,7 @@
 cmdLine.addArgument("${file}");
 HashMap map = new HashMap();
 map.put("file", new File("invoice.pdf"));
-commandLine.setSubstitutionMap(map);
+cmdLine.setSubstitutionMap(map);
 
 DefaultExecuteResultHandler resultHandler = new DefaultExecuteResultHandler();