function validRequired(formField,fieldLabel) {
    var result = true;
    if (formField.value == "") {
      alert('Please enter a value for the "' + fieldLabel +'" field.');
      formField.focus();
      result = false;
    }
    return result;
  }

  function allDigits(str) {
    return inValidCharSet(str,"0123456789");
  }

  function inValidCharSet(str,charset) {
    var result = true;
    for (var i=0;i<str.length;i++)
      if (charset.indexOf(str.substr(i,1))<0) {
        result = false;
	break;
      }
    return result;
  }

    function isValidExpDate(formName,fieldName) {
	    var result = false;
	    var formValue = "";
	    var month = -1;
	    var year = -1;
	    eval("formValue = document."+formName+"." + fieldName + ".value");
	    var curr_dt = new Date();
	    var exp_dt = new Date();
//	alert("exp dt = " + formValue);
//	alert("curr dt = " + curr_dt);
//	alert("exp dt = " + exp_dt); 
		var elems = formValue.split("/");
		result = (elems.length == 2); // should be two components
		var expired = false;
		    month = parseInt(elems[0],10);
		    year = parseInt(elems[1],10);
		    var tod = new Date();
		    var nowMonth = tod.getMonth();
		    var nowYear = tod.getFullYear();

		    exp_dt.setYear(year);
		    exp_dt.setMonth(month);


		    if (exp_dt > curr_dt) {
			expired = false;
		    } else {
			expired = true;
		    }
		    if (expired) {
			alert('Please enter a valid expiry date.');
			return false;
		    }
		    return true;
    }

function isValidCreditCardNumber(formName,cardNumber,ccType) {
    var result = true;
    eval("var ccNum = document."+formName+"." + cardNumber + ".value");
    eval("var cctyp = document."+formName+"." + ccType + ".value");
    if (cctyp == "-") {
          alert('Please select a Credit Card Type.');		  
	   eval("document."+formName+ "." + ccType + ".focus()");
	   result = false;
	  return false;
    }
    if (ccNum.length>0) { 
        if (!allDigits(ccNum)) {
          alert('Please enter only numbers (no dashes or spaces) in Credit Card Number.');
            eval("document."+formName+"." + cardNumber + ".select()");
            result = false;
	  return false;
        }	
        if (result) { 
//	  if (!LuhnCheck(ccNum) || !validateCCNum(cctyp,ccNum)) {
	  if (!validateCCNum(cctyp,ccNum)) {
 	    alert('Please enter a valid card number.');
            eval("document."+formName+"." + cardNumber + ".select()");
            result = false;
	    return false;
	  }	
        }
      } else {
        alert('Please enter card number.');
        eval("document."+formName+"." + cardNumber + ".focus()");
	  return false;
      }
    return result;
  }

  function LuhnCheck(str) {
    var result = true;
    var sum = 0; 
    var mul = 1; 
    var strLen = str.length;
    alert(strLen);
  
    for (i = 0; i < strLen; i++) {
      var digit = str.substring(strLen-i-1,strLen-i);
      var tproduct = parseInt(digit ,10)*mul;
      if (tproduct >= 10)
        sum += (tproduct % 10) + 1;
      else
        sum += tproduct;
      if (mul == 1)
        mul++;
      else
        mul--;
    }
    if ((sum % 10) != 0)
        result = false;
        alert('result'+result);
    return result;
  }

  function GetRadioValue(rArray) {
    for (var i=0;i<rArray.length;i++) {
      if (rArray[i].checked)
        return rArray[i].value;
    }
    return null;
  }

  function validateCCNum(cardType,cardNum) {
    var result = false;
    cardType = cardType.toUpperCase();
    var cardLen = cardNum.length;
    var firstdig = cardNum.substring(0,1);
    var seconddig = cardNum.substring(1,2);
    var first4digs = cardNum.substring(0,4);
    switch (cardType) {
      case "VISA":
        result = ((cardLen == 16) || (cardLen == 13)) && (firstdig == "4");
	break;
      case "AMEX":
        var validNums = "47";
	result = (cardLen == 15) && (firstdig == "3") && (validNums.indexOf(seconddig)>=0);
	break;
      case "MASTERCARD":
	var validNums = "12345";
	result = (cardLen == 16) && (firstdig == "5") && (validNums.indexOf(seconddig)>=0);
	break;
      case "DISCOVER":
	result = (cardLen == 16) && (first4digs == "6011");
	break;
      case "DINERS":
	var validNums = "068";
	result = (cardLen == 14) && (firstdig == "3") && (validNums.indexOf(seconddig)>=0);
	break;
      }
      return result;
    }

    function ccExpDateValid(formName, ccMonth, ccYear, ccExp) {
         eval("var exp_year = document."+formName+"." + ccYear + ".value");
         eval("var exp_month = document."+formName+"." + ccMonth + ".value");
         eval("document."+formName+"."+ccExp+".value='"+exp_month+"/"+exp_year+"'");
    }