Fix error spotted by m4n_in_bl4ck in the forum.

doc/skins/skins2-howto.xml

@@ -932,7 +932,7 @@ difficulty to understand how VLC skins work.</para>
     <emphasis>dvd.nextChapter()</emphasis>: Go to the next chapter of the DVD (since VLC 0.8.5).
   </para></listitem>
   <listitem><para>
-    <emphasis>dvd.previousTitle()</emphasis>: Go to the previous chapter of the DVD (since VLC 0.8.5).
+    <emphasis>dvd.previousChapter()</emphasis>: Go to the previous chapter of the DVD (since VLC 0.8.5).
   </para></listitem>
   <listitem><para>
     <emphasis>dvd.rootMenu()</emphasis>: Go to the root menu of the DVD (since VLC 0.8.5).