#!/usr/athena/bin/perl

use strict;

while (<>) {
    chomp;
    system "mv $_ $_.old";
    open (MYIN, "<", "$_.old");
    open (MYOUT, ">", "$_");
    while (my $mline = <MYIN>) {
	chomp ($mline);
	if ($mline =~ /\<P\>(.*)$/) {
	    print MYOUT "<A HREF=../periodic-table.html>Go back to the periodic table.</A>";
	} else {
	    print MYOUT $mline;
	}
	print MYOUT "\n";
    }
    close (MYIN);
    close (MYOUT);
}