if( $bookXML eq '' ) { $bookXML = "$language/xml/$bookCode.xml"; }
if( $xhtmlXSL eq '' ) { die "Unspecified XSL transformation file\n$USAGE"; }
if( $bookXML eq '' ) { $bookXML = "$language/xml/$bookCode.xml"; }
if( $xhtmlXSL eq '' ) { die "Unspecified XSL transformation file\n$USAGE"; }