resolucion=screen.width
function estilo( resolucion) {
	document.write( '<link rel="stylesheet" href="canta' );
	if ( resolucion>=1280) {
		document.write ( '1280' );
	}
	if ( resolucion<1280 && resolucion>=1024 ) {
		document.write ( '1024' );
	}
	if ( resolucion<1024 ) {
		document.write ( '800' );
	}
	document.write( '.css" type="text/css">' );
}

estilo ( resolucion );