validation error fixes
diff --git a/user_guide/overview/appflow.html b/user_guide/overview/appflow.html
index d95d8c7..8e1d606 100644
--- a/user_guide/overview/appflow.html
+++ b/user_guide/overview/appflow.html
@@ -60,7 +60,7 @@
<p>The following graphic illustrates how data flows throughout the system:</p>
-<div><img src="../images/appflowchart.gif" width="697" height="205" border="0" /></div>
+<div><img src="../images/appflowchart.gif" width="697" height="205" border="0" alt="CodeIgniter application flow" /></div>
<ol>