function checkCardType(cType,cNumber) {	
	var cDigit = Left(cNumber, 1);	
	var cLen = cNumber.length;
	
	if ((cType != "") && (cNumber != "")) {
		//alert(cType);
		//alert(cNumber);
		//alert(cLen);
		//alert(cDigit);
		
		switch(cType){
			case 'MasterCard':
				//return CardType("MasterCard", "51,52,53,54,55", "16");
				if (cLen == 16) {
					if (cDigit == 5) {
						return true;	
					}
				}
				break;
			case 'VisaCard':
				//return CardType("VisaCard", "4", "13,16");
				if ((cLen == 13) || (cLen == 16)) {
					if (cDigit == 4) {
						return true;
					}
				}
				break;
			case 'AmExCard':
				//return CardType("AmExCard", "34,37", "15");
				if (cLen == 15) {
					if (cDigit == 3) {
						return true;	
					}
				}
				break;
			case 'DiscoverCard':
				//return CardType("DiscoverCard", "6011", "16");
				if (cLen == 16) {
					if (cDigit == 6) {
						return true;	
					}
				}
				break;
			default:
				return false;
				break;
		}
	} else {
		//alert("bad type");
		return false;
	}
}

function Left(str, n){
	if (n <= 0)
	    return "";
	else if (n > String(str).length)
	    return str;
	else
	    return String(str).substring(0,n);
}
function Right(str, n){
    if (n <= 0)
       return "";
    else if (n > String(str).length)
       return str;
    else {
       var iLen = String(str).length;
       return String(str).substring(iLen, iLen - n);
    }
}


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

var errordcode = "";*/