var Cards = new makeArray(8);
Cards[0] = new D2("MasterCard", "51,52,53,54,55", "16");
var MasterCard = Cards[0];
Cards[1] = new D2("VisaCard", "4", "13,16");
var VisaCard = Cards[1];
Cards[2] = new D2("AmExCard", "34,37", "15");
var AmExCard = Cards[2];
Cards[3] = new D2("DinersClubCard", "30,36,38", "14");
var DinersClubCard = Cards[3];
Cards[4] = new D2("DiscoverCard", "6011", "16");
var DiscoverCard = Cards[4];
Cards[5] = new D2("enRouteCard", "2014,2149", "15");
var enRouteCard = Cards[5];
Cards[6] = new D2("JCBCard", "3088,3096,3112,3158,3337,3528", "16");
var JCBCard = Cards[6];
var LuhnCheckSum = Cards[7] = new D2();

function CheckT14(form) {
  var tmpyear;
  if (form.T14.value.length == 0) {
	  if (form.T13.value.length == 0) {
    	  	return true;
    	  }else{
    	  	alert("Introduzca el número de tarjeta");
    	  return false;
    	  }
  }
  if(form.ano_cad.selectedIndex==0||form.mes_cad.selectedIndex==0){
    alert("Introduzca la fecha de caducidad.");
    return false;
  }
  tmpyear = form.ano_cad.options[form.ano_cad.selectedIndex].text;
  tmpmonth = form.mes_cad.options[form.mes_cad.selectedIndex].text;
  if (!(new D2()).isExpiryDate(tmpyear, tmpmonth)) {
    alert("Fecha de caducidad ya sobrepasada.");
    return false;
  }
  card = form.D2.options[form.D2.selectedIndex].value;
  var retval = eval(card + ".checkT14(\"" + form.T14.value +
        "\", " + tmpyear + ", " + tmpmonth + ");");

  cardname = "";
  if (retval){
    return true;
  }else {
    for (var n = 0; n < Cards.size; n++) {
      if (Cards[n].checkT14(form.T14.value, tmpyear, tmpmonth)) {
        cardname = Cards[n].getD2();
        break;
      }
    }
    if (cardname.length > 0) {
      alert("Este es un número " + cardname + ", no " + card);
    }
    else {
      alert("El número de tarjeta no es correcto.");
    }
  }
}

function D2() {
  var n;
  var argv = D2.arguments;
  var argc = D2.arguments.length;

  this.objname = "object D2";

  var tmpD2 = (argc > 0) ? argv[0] : "CardObject";
  var tmprules = (argc > 1) ? argv[1] : "0,1,2,3,4,5,6,7,8,9";
  var tmplen = (argc > 2) ? argv[2] : "13,14,15,16,19";

  this.setT14 = setT14;

  this.setD2 = setD2;

  this.setLen = setLen;

  this.setRules = setRules;

  this.setExpiryDate = setExpiryDate;

  this.setD2(tmpD2);
  this.setLen(tmplen);
  this.setRules(tmprules);
  if (argc > 4)
    this.setExpiryDate(argv[3], argv[4]);

  this.checkT14 = checkT14;

  this.getExpiryDate = getExpiryDate;

  this.getD2 = getD2;

  this.isT14 = isT14;

  this.isExpiryDate = isExpiryDate;

  this.luhnCheck = luhnCheck;

  return this;
}

function checkT14() {
  var argv = checkT14.arguments;
  var argc = checkT14.arguments.length;
  var T14 = (argc > 0) ? argv[0] : this.T14;
  var year = (argc > 1) ? argv[1] : this.year;
  var month = (argc > 2) ? argv[2] : this.month;

  this.setT14(T14);
  this.setExpiryDate(year, month);

  if (!this.isT14())
    return false;

  if (!this.isExpiryDate())
    return false;

  return true;
}

function getD2() {
  return this.D2;
}

function getExpiryDate() {
  return this.month + "/" + this.year;
}

function isT14() {
  var argv = isT14.arguments;
  var argc = isT14.arguments.length;
  var T14 = (argc > 0) ? argv[0] : this.T14;

  if (!this.luhnCheck())
    return false;

  for (var n = 0; n < this.len.size; n++)
    if (T14.toString().length == this.len[n]) {
      for (var m = 0; m < this.rules.size; m++) {
        var headdigit = T14.substring(0, this.rules[m].toString().length);
        if (headdigit == this.rules[m])
          return true;
      }
      return false;
    }

  return false;
}

function isExpiryDate() {
  var argv = isExpiryDate.arguments;
  var argc = isExpiryDate.arguments.length;

  year = argc > 0 ? argv[0] : this.year;
  month = argc > 1 ? argv[1] : this.month;

  if (!isNum(year+""))
    return false;
  if (!isNum(month+""))
    return false;
  today = new Date();
  expiry = new Date(year, month);
  if (today.getTime() > expiry.getTime())
    return false;
  else
    return true;
}

function isNum(argvalue) {
  argvalue = argvalue.toString();

  if (argvalue.length == 0)
    return false;

  for (var n = 0; n < argvalue.length; n++)
    if (argvalue.substring(n, n+1) < "0" || argvalue.substring(n, n+1) > "9")
      return false;

  return true;
}

function luhnCheck() {
  var argv = luhnCheck.arguments;
  var argc = luhnCheck.arguments.length;

  var T14 = argc > 0 ? argv[0] : this.T14;

  if (! isNum(T14)) {
    return false;
  }

  var no_digit = T14.length;
  var oddoeven = no_digit & 1;
  var sum = 0;

  for (var count = 0; count < no_digit; count++) {
    var digit = parseInt(T14.charAt(count));
    if (!((count & 1) ^ oddoeven)) {
      digit *= 2;
      if (digit > 9)
	digit -= 9;
    }
    sum += digit;
  }
  if (sum % 10 == 0)
    return true;
  else
    return false;
}

function makeArray(size) {
  this.size = size;
  return this;
}

function setT14(T14) {
  this.T14 = T14;

  return this;
}

function setD2(D2) {
  this.D2 = D2;

  return this;
}

function setExpiryDate(year, month) {
  this.year = year;
  this.month = month;

  return this;
}

function setLen(len) {
  if (len.length == 0 || len == null)
    len = "13,14,15,16,19";

  var tmplen = len;
  n = 1;
  while (tmplen.indexOf(",") != -1) {
    tmplen = tmplen.substring(tmplen.indexOf(",") + 1, tmplen.length);
    n++;
  }
  this.len = new makeArray(n);
  n = 0;
  while (len.indexOf(",") != -1) {
    var tmpstr = len.substring(0, len.indexOf(","));
    this.len[n] = tmpstr;
    len = len.substring(len.indexOf(",") + 1, len.length);
    n++;
  }
  this.len[n] = len;

  return this;
}

function setRules(rules) {
  if (rules.length == 0 || rules == null)
    rules = "0,1,2,3,4,5,6,7,8,9";
  
  var tmprules = rules;
  n = 1;
  while (tmprules.indexOf(",") != -1) {
    tmprules = tmprules.substring(tmprules.indexOf(",") + 1, tmprules.length);
    n++;
  }
  this.rules = new makeArray(n);
  n = 0;
  while (rules.indexOf(",") != -1) {
    var tmpstr = rules.substring(0, rules.indexOf(","));
    this.rules[n] = tmpstr;
    rules = rules.substring(rules.indexOf(",") + 1, rules.length);
    n++;
  }
  this.rules[n] = rules;

  return this;
}
function esEmail(pcadena)
{
	var arroba;
	var longitud;
	var punto;

	arroba = pcadena.indexOf("@");
	longitud = pcadena.length;
	punto = pcadena.lastIndexOf(".");

	if (longitud == 0) return false;
	if (arroba == -1 || arroba == 0) return false;
	if (longitud - arroba < 5) return false;
	if (longitud - punto !=3 && longitud - punto !=4) return false;
	return true;
}