[manual] for in structures

[Francesco Potorti`]

In Data Structures I propose to use a more precise reference:

diff -r de8b07e95d1b doc/interpreter/container.txi
--- a/doc/interpreter/container.txi	Mon Sep 22 13:38:15 2008 -0400
+++ b/doc/interpreter/container.txi	Tue Sep 23 16:47:12 2008 +0200
@@ -208,7 +208,7 @@ x.v =
 
 It is also possible to cycle through all the elements of a structure in
 a loop, using a special form of the @code{for} statement
-(@pxref{The for Statement})
+(@pxref{Looping Over Structure Elements})
 
 @menu
 * Structure Arrays::