Clarify the prompt in an example.

This closes SF bug #450633.

Doc/tut/tut.tex

@@ -1042,7 +1042,7 @@ Perhaps the most well-known statement type is the
 \keyword{if} statement.  For example:
 
 \begin{verbatim}
->>> x = int(raw_input("Please enter a number: "))
+>>> x = int(raw_input("Please enter an integer: "))
 >>> if x < 0:
 ...      x = 0
 ...      print 'Negative changed to zero'