function isCardDetailsFilled()
{
	return (
		(document.forms[0].cardtype.selectedIndex != 0) ||
		(trim(document.forms[0].creditCardNumber.value)!="") ||
		(document.forms[0].startmonth.selectedIndex!=0) ||
		(document.forms[0].creditCardStartDateYear.selectedIndex !=0) ||
		(document.forms[0].creditCardExpiryMonth.selectedIndex!=0) ||
		(document.forms[0].creditCardExpiryYear.selectedIndex!=0) ||
		(trim(document.forms[0].issueNumber.value)!="") ||
		(trim(document.forms[0].cardholder.value)!="")
	);
}

function checkcardnumber()
{
	if (isCardDetailsFilled())
	{
		errorNotNumber = (!isDigitOnly(trim(document.forms[0].creditCardNumber.value)));
		checkCardNumber = trim(document.forms[0].creditCardNumber.value);
		return (errorNotNumber || checkCardNumber.length <= 15 || checkCardNumber.length > 20);
	}
	else
	{
		return false;
	}
}

function startdate_errors()
{
	var month = document.forms[0].creditCardStartDateMonth.selectedIndex;
	var year = document.forms[0].creditCardStartDateYear.selectedIndex;
	
	if ((month == 0 && year != 0) || (month != 0 && year == 0))
		return true;
	else
		return false;
}

function expiry_errors()
{
	if (isCardDetailsFilled())
	{
		return (document.forms[0].creditCardExpiryMonth.selectedIndex==0 || document.forms[0].creditCardExpiryYear.selectedIndex==0);
	}
	else
	{
		return false;
	}
}

function issueNumber_errors()
{	
	var issueNo = trim(document.forms[0].issueNumber.value);
	
	if (issueNo.length > 0)
	{
		return (!isDigitOnly(document.forms[0].issueNumber.value));
	}
	else
	{
		return false;
	}	
}

function cardholder_errors()
{
	return ((isCardDetailsFilled()) && (trim(document.forms[0].cardholder.value)==""));
}

function isBankDetailsFilled()
{
	return (
		(trim(document.forms[0].bankAccountName.value)!="") ||
		(trim(document.forms[0].bankName.value)!="") ||
		(trim(document.forms[0].bankSortCode1.value)!="") ||
		(trim(document.forms[0].bankSortCode2.value)!="") ||
		(trim(document.forms[0].bankSortCode3.value)!="") ||
		(trim(document.forms[0].bankAccountNumber.value)!="")
	);
}

function bankAccountName_errors()
{
	return (isBankDetailsFilled() && (trim(document.forms[0].bankAccountName.value) == ""));
}

function bankName_errors()
{
	return (isBankDetailsFilled() && (trim(document.forms[0].bankName.value) == ""));
}

function sortcode_errors()
{
	if (isBankDetailsFilled())
	{
		var sortCode1 = trim(document.forms[0].bankSortCode1.value);
		var sortCode2 = trim(document.forms[0].bankSortCode2.value);
		var sortCode3 = trim(document.forms[0].bankSortCode3.value);		
		var completeSortCode = sortCode1 + sortCode2 + sortCode3;
	
		return (completeSortCode.length != 6 || !isDigitOnly(completeSortCode));
	}
	else
	{
		return false;
	}
}

function bankAccountNumber_errors()
{
	if (isBankDetailsFilled())
	{
		var accountNo = trim(document.forms[0].bankAccountNumber.value);

		return (!isDigitOnly(accountNo) || accountNo.length <= 6);
	}
	else
	{
		return false;
	}           
}