use HTML::TokeParser::Simple;

my $page = ...;
my $alternative = find_alternate_page( $page );

sub find_alternate_page {
	my $page = shift;
	return undef unless $page;
	my $p = HTML::TokeParser::Simple->new( \$page );
	my $looking = 0;
	while ( my $token = $p->get_token ) {
		 $looking = 1 if $token->is_start_tag( 'noframes' );
		 return undef if $token->is_end_tag( 'noframes' );
		if ( $looking && $token->is_start_tag( 'a' ) ) {
			return $token->return_attr->{href};
		}
	}
}