Fix html manual for the Packard Bell Vibe 500.

Change-Id: I1f39cb93081738e757101cdf6aeb5e3a1ca0e42c
diff --git a/manual/plugins/xworld.tex b/manual/plugins/xworld.tex
index 4ea7559..cd48601 100644
--- a/manual/plugins/xworld.tex
+++ b/manual/plugins/xworld.tex
@@ -18,7 +18,7 @@
     \opt{IPOD_4G_PAD,IPOD_3G_PAD,IPOD_1G2G_PAD}{\ButtonMenu}
     \opt{IRIVER_H10_PAD}{\ButtonScrollUp}
     \opt{HAVE_TOUCHSCREEN}{\TouchTopMiddle}
-    \opt{PBELL_VIBE500_PAD}{\ButtonOk}
+    \opt{PBELL_VIBE500_PAD}{\ButtonOK}
        \opt{HAVEREMOTEKEYMAP}{& }
     & Up and Jump \\
     %