var payment_choice = 0


function updateTotal()
	{
		total = 0
		discountAmount = 0
		
		switch(payment_choice){
			case 1:
				total = 20
				break
			case 2:
				total = 250
				break
				case 3:
				total = 1600
				break
				case 4:
				total = document.form1.deposit_option.value
				break
			default:
				total = 0
				break
		}		

		document.form1.total_payment.value = "$" + total
		
	}

	
	function paymentClicked(paytype)
	{
		switch (paytype)
		{
		case 1:
			document.form1.deposit_option.value = ""
			document.form1.deposit_option.disabled = true
			payment_choice = 1
			break
		case 2:			
			document.form1.deposit_option.value = ""
			document.form1.deposit_option.disabled = true
			payment_choice = 2
			break
		case 3:
			document.form1.deposit_option.value = ""
			document.form1.deposit_option.disabled = true
			payment_choice = 3
			break
		case 4:
			document.form1.deposit_option.disabled = false
			payment_choice = 4
			break
		}
		updateTotal()
	}


	function isEmpty(inputStr)
	{
		if (inputStr == null || inputStr =="") {
			return true
		}
		return false
	}
	
	function emptyField(field, label)
	{
		if (isEmpty(field.value)) {
			alert("Please enter a value in the " + label + " box.")
			return true
		}
		return false
	}
					
	function cardTypeOK(cardType) {
		if (cardType.value == 'select') {
			alert("Please enter your credit card type.")
			return false
		}
		return true
	}
	
	function cardNumberOK(cardNumber)
	{
		if (cardNumber.value.length != 16) {
			alert("There should be 16 digits (no spaces) in the credit card number.")
			return false
		}
		return true
	}
	
	function integerRangeOK(field, minValue, maxValue, label)
	{
		if (isEmpty(field.value)) {
			alert("Please enter a value in the " + label + " box.")
			return false
		}

		if (!IsNumber(field.value, true)) {
          		alert("Please enter only numbers for " + label);
            		field.focus();
            		return false;			
         	}
		

		number = parseInt(field.value)
		if (number < minValue || number > maxValue) {
			alert("The " + label + " should be in the range " + minValue.toString() + " to " + maxValue.toString() + ".")
			return false 
		}
		return true
	}
	
	function checkForm(form)
	{
		if (emptyField(form.surname, 'Surname')) {
			return false
		}
		if (emptyField(form.firstname, 'First Name')) {
			return false
		}
		if (emptyField(form.address1, 'Address')) {
			return false
		}
		if (emptyField(form.address2, 'City')) {
			return false
		}
		if (emptyField(form.postcode, 'Postcode')) {
			return false
		}
		if (emptyField(form.workphone, 'Phone')) {
			return false
		}

         	if (!IsNumber(form.workphone.value, true)) {
          		alert("Please enter only numbers for your Phone");
            		form.workphone.focus();
            		return false;			
         	}


		if (emptyField(form.email, 'Email')) {
			return false
		}

 		if ( !isEmail(form.email.value) ) {
            		alert("Please enter a valid Email Address.");
            		form.email.focus();
            		return false;
         	}
		
		if(payment_choice == 0){
			alert("Please select a donation option");            		
            		return false;	
		}

		if (payment_choice == 4)
		{		

			if (emptyField(form.deposit_option, 'amount')) {
			return false;
			}

			if (!IsNumber(form.deposit_option.value, true)) {
          		alert("Please enter only numbers for your amount");
            		form.deposit_option.focus();
            		return false;			
	         	}
		}


		if (!cardTypeOK(form.card_type)){
			return false
		}
		
		if (!cardNumberOK(form.card_number)){
			return false
		}

		if (emptyField(form.cvv_number, 'CVV Number')) {
			return false
		}

         	if (!IsNumber(form.cvv_number.value, true)) {
          		alert("Please enter only numbers for the CVV Number");
            		form.cvv_number.focus();
            		return false;			
         	}

				
		if (emptyField(form.card_name, "Cardholder's Name")) {
			return false
		}
		if (!integerRangeOK(form.card_expiry_month, 1, 12, "card expiry month")) {
			return false
		}
		if (!integerRangeOK(form.card_expiry_year, 2, 20, "card expiry year")) {
			return false
		}
		return true
	}