#!/bin/sh echo Content-type: text/html echo N=$QUERY_STRING echo "" case "x$N" in x) N=1 echo "This is the initial page.

" ;; x[0-9]*) N=`expr $N + 1` echo "You have refreshed this page $N times.

" ;; *) echo "The URL you used is invalid." exit 0 ;; esac echo "" echo "Click here to refresh the page."