sub URI_ESCAPE {
	my ($text) = @_;
	return undef unless defined $text;
	my (%escapes);
	for (0..255) { $escapes{chr($_)} = sprintf("%%%02X", $_) }
	$text =~ s/([^;\/?:@&=+\$,A-Za-z0-9\-_.!~*'()])/$escapes{$1}/g;
	$text;
}