function isNumeric(strString)
   //  check for valid numeric strings	
   {
   var strValidChars = "0123456789.-";
   var strChar;
   var blnResult = true;

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

   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++)
      {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
         {
         blnResult = false;
         }
      }
   return blnResult;
   }

function validCreditCard(cardNumber, cardType)
{
  var isValid = false;
  var ccCheckRegExp = /[^\d ]/;
  isValid = !ccCheckRegExp.test(cardNumber);

  if (isValid)
  {
    var cardNumbersOnly = cardNumber.replace(/ /g,"");
    var cardNumberLength = cardNumbersOnly.length;
    var lengthIsValid = false;
    var prefixIsValid = false;
    var prefixRegExp;

    switch(cardType)
    {
      case "Mastercard":
        lengthIsValid = (cardNumberLength == 16);
        prefixRegExp = /^5[1-5]/;
        break;

      case "Visa":
        lengthIsValid = (cardNumberLength == 16 || cardNumberLength == 13);
        prefixRegExp = /^4/;
        break;

      case "American Express":
        lengthIsValid = (cardNumberLength == 15);
        prefixRegExp = /^3(4|7)/;
        break;

      case "Discover":
        lengthIsValid = (cardNumberLength == 16);
        prefixRegExp = /^6/;
        break;
				
      default:
        prefixRegExp = /^$/;
        //alert("Card type not found");
    }

    prefixIsValid = prefixRegExp.test(cardNumbersOnly);
    isValid = prefixIsValid && lengthIsValid;
  }

  if (isValid)
  {
    var numberProduct;
    var numberProductDigitIndex;
    var checkSumTotal = 0;

    for (digitCounter = cardNumberLength - 1; 
      digitCounter >= 0; 
      digitCounter--)
    {
      checkSumTotal += parseInt (cardNumbersOnly.charAt(digitCounter));
      digitCounter--;
      numberProduct = String((cardNumbersOnly.charAt(digitCounter) * 2));
      for (var productDigitCounter = 0;
        productDigitCounter < numberProduct.length; 
        productDigitCounter++)
      {
        checkSumTotal += 
          parseInt(numberProduct.charAt(productDigitCounter));
      }
    }

    isValid = (checkSumTotal % 10 == 0);
  }

  return isValid;
}
	 

function validEmail(strEmail){
	//var str=document.validation.emailcheck.value
	var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
	if (filter.test(strEmail))
		 testresults=true
	else {
		testresults=false
	}
	return (testresults)
}