var lang_en = [
  "There is no name.",
  "There is no email address.",
  "There is no subject.",
  "There is no message.",
  "The email address is invalid.",
  "No language selected.",
  "There is no URL (website address)"
];

var lang_it = [
  "Manca il nome.",
  "Manca l'indirizzo email.",
  "Manca il soggetto.",
  "Manca il messaggio.",
  "L'indirizzo email non è valido.",
  "Selezionate un linguaggio.",
  "Manca l'URL (indirizzo del sito)"
];

function testAddress(src) {
   var emailReg = "^[\\w-_\.]*[\\w-_\.]\@[\\w]\.+[\\w]+[\\w]$";
   var regex = new RegExp(emailReg);
   return regex.test(src);
}

function checkEmailContact(lang)
{
  if (lang == 'en') { language = lang_en; }
  if (lang == 'it') { language = lang_it; }
  var message = '';
  var form = document.contactform;
  if (form.name.value.length == 0) { message += language[0] + "\n"; }
  if (form.address.value.length == 0) { message += language[1] + "\n"; }
  if (form.subject.value.length == 0) { message += language[2] + "\n"; }
  if (form.text.value.length == 0) { message += language[3] + "\n"; }
  if (testAddress(form.address.value) == 0) { message += language[4] + "\n"; } 
  if (message.length > 0) { alert(message); return false;}
  else { return true; }
}