in evidence:

if (navigator.userLanguage) {theAgent = navigator.userLanguage;} else {theAgent = navigator.language;} if (theAgent.indexOf('en') != -1) {document.location.href = 'html/cambialingua.php?lingua=en';} if (theAgent.indexOf('fr') != -1) {document.location.href = 'html/cambialingua.php?lingua=fr';} if (theAgent.indexOf('es') != -1) {document.location.href = 'html/cambialingua.php?lingua=es';} if (theAgent.indexOf('de') != -1) {document.location.href = 'html/cambialingua.php?lingua=de';} if (theAgent.indexOf('it') != -1) {document.location.href = 'html/cambialingua.php?lingua=it';}