function CartForm() {
    this.step = 1;
    this.payType = "";

    this.overview = document.getElementById('overview');
    this.checkoutCart = document.getElementById('checkoutCart');
    this.SubmitOrder = document.getElementById('SubmitOrder');
    this.errorMessage = document.getElementByClassName('p', 'errormessage');
    this.personalDetails = document.getElementById('personalDetails');
    this.paymenttype = document.getElementById('paymenttype');
    this.information = document.getElementById('information');
    this.formCreditCard = document.getElementById('formCreditCard');
    this.formSchoolInvoice = document.getElementById('formSchoolInvoice');
    this.checkoutConfirmation = document.getElementById('checkoutConfirmation');

    if (typeof CartForm._initialized == "undefined") {
        CartForm.prototype.hideAll = function () {
            this.overview.style.display = "none";
            this.checkoutCart.style.display = "none";
            this.errorMessage.style.display = "none";
            this.personalDetails.style.display = "none";
            this.paymenttype.style.display = "none";
            this.information.style.display = "none";
            this.formCreditCard.style.display = "none";
            this.formSchoolInvoice.style.display = "none";
            this.checkoutConfirmation.style.display = "none";

            if ((this.step == 2) && (this.payType == "3")) {
                var oExtras = document.getInnerElementByClassName(this.formSchoolInvoice, 'div', 'formExtras');
                oExtras.style.display = "block";
                oExtras = document.getInnerElementByClassName(this.formCreditCard, 'div', 'formExtras');
                oExtras.style.display = "none";
            }
        };

        CartForm.prototype.goTo2 = function () {
            if (!oCart.loaded) return false;

            if (this.payType == "2" && oCart.hasInspectedItem()) {
                alert("Inspection copies may only be requested by schools.");
                return false;
            }
            if (this.payType == "3" && oCart.hasInspectedItem()) {
                alert("Inspect on Approval items cannot be ordered using credit card for payment. Please select payment by invoice or remove these items.");
                return false;
            }

            var validate = this.validateStep1();
            if (!validate) return false;

            this.hideAll();
            this.step++;
            this.overview.innerHTML = "";
            if (this.payType == "2") {
                var oText = '<h2>Personal Credit Card details</h2><p class="beforeCart">';
                oText += 'Please enter your payment details.<br />';
                if ((typeof checkTC != "undefined") && (checkTC == true)) {
                    oText += '<span>Your total charge will be $' + oCart.getEClubTotal() + '</span>';
                } else {
                    oText += '<span>Your total purchase is $' + (Number(oCart.getTotal()) - oCart.handlingCharge).toFixed(2) + '</span><br /><br />';
                    oText += 'A handling charge of <span>$' + oCart.handlingCharge + '</span> applies to personal orders.<br />';
                    oText += '<span>Your total charge will be $' + (Number(oCart.getTotal())).toFixed(2) + '</span>';
                }
                oText += '</p>';
                this.overview.innerHTML = oText;
                this.overview.style.display = "block";
                this.formCreditCard.style.display = "block";

            } else {
                var oText = '<h2>School/University invoice details</h2><p class="beforeCart">';

                oText += 'Please enter your payment details.<br />';
                if ((typeof checkTC != "undefined") && (checkTC == true)) {
                    oText += '<span>Your total purchase is $' + oCart.getEClubTotal() + '</span><br /><br />';
                } else {
                    oText += '<span>Your total purchase is $' + oCart.getTotal() + '</span><br /><br />';
                }
                oText += '</p>';
                this.overview.innerHTML = oText;
                this.overview.style.display = "block";

                this.formSchoolInvoice.style.display = "block";

            }
            oCart.updateShoppingSummary();
        };

        CartForm.prototype.next = function () {

            var payTypeList = document.forms['SubmitOrder'].CustomField_4;

            for (var i = 0; i < payTypeList.length; i++) {
                if (payTypeList[i].checked) this.payType = payTypeList[i].value;
            }

            if (this.payType == '') {
                alert('Please select a payment method.');
                return false;
            }

            if ((this.payType == '2' || this.payType == '3') && this.step == 1) this.step = 2; //adjust step for credit card payment


            if (this.step == 1) {

                this.goTo2();
            } else if (this.step == 2) {
                var bValidate = false;

                /*if((this.payType == "2" || this.payType=="3") && isOutOfStockOnly())             
                {
                alert('Items not available cannot be purchased by credit card. Select payment by invoice.');
                return false;
                }*/

                if (this.payType == "2") {
                    if (oCart.hasInspectedItem()) {
                        alert("Inspection copies may only be requested by schools.");
                        this.step = 1;
                        return false;
                    }
                    bValidate = this.validateStep1();
                    //bValidate = true;
                } else if (this.payType == "4") {
                    bValidate = this.validateInvoice();
                } else {
                    //bValidate = this.validateInvoice();
                    bValidate = this.validateStep1();
                }
                if (bValidate) {

                    /*if ((this.payType=="2" || this.payType=="3") && isMixedOrder()) {
                    // remove not available itmes 
                    for(var i=0; i < oCart.items.length; i++) {
                    if (!oCart.items[i].available) oCart.deleteFromCart(oCart.items[i].isbn);
                    }
                    } */

                    this.hideAll();
                    var tmpAddressType = getAddressType();
                    if (tmpAddressType == "1") {
                        document.forms['SubmitOrder'].Organisation.value = "";
                    }



                    this.step++;
                    var oText = "<h2>Checkout Purchase confirmation</h2>";

                    if (typeof oCart != "undefined") {
                        oText += oCart.getCheckoutConfirmationTable();
                        if (this.payType == '2') {
                            oText += '<p>A handling fee of $10.00 applies for private customers.</p>';
                        }
                        oText += this.getDeliverySummary();
                        oText += '<p><input type="button" onclick="previous(event)" class="previousStep" value="Previous step" /></p>';
                        oText += '<p><input type="submit" class="previousStep" value="Purchase now" /></p>';
                        this.checkoutConfirmation.innerHTML = oText;
                        this.checkoutConfirmation.style.display = "block";

                        var summaryCartTotal = document.getElementById('total');
                        if (summaryCartTotal) summaryCartTotal.innerHTML = 'Current total: $' + oCart.getTotal();
                    }

                }
            } else {
                this.submit();
            }
        };
        CartForm.prototype.previous = function () {
            this.hideAll();
            if ((this.payType == '2' || this.payType == '3') && this.step == 3) {
                this.step = 1;
            } else {
                this.step--;
            }

            if (this.step == "1") {
                this.overview.innerHTML = "";
                var oText = '<h2>Overview</h2><p class="beforeCart">';
                oText += 'If you are a Teacher e-Club member and not logged in, <a href="libraries/Teachers+Club" title="Teachers Club">login</a> now to receive your discount.<br />';
                oText += 'Non members, <a href="ibraries/Teachers+Club" title="Teachers Club">register</a> now.<br />';
                oText += 'Inspection copies can be made by schools only.';
                oText += '</p>';
                this.overview.innerHTML = oText;
                oCart.updateShoppingSummary();
                this.overview.style.display = "block";
                this.checkoutCart.style.display = "block";
                this.paymenttype.style.display = "block";
                this.personalDetails.style.display = "block";
                this.information.style.display = "block";
            } else {

                var oText = '<h2>School/University invoice details</h2><p class="beforeCart">';

                oText += 'Please enter your payment details.<br />';
                if ((typeof checkTC != "undefined") && (checkTC == true)) {
                    oText += '<span>Your total purchase is $' + oCart.getEClubTotal() + '</span><br /><br />';
                } else {
                    oText += '<span>Your total purchase is $' + oCart.getTotal() + '</span><br /><br />';
                }
                oText += '</p>';
                this.overview.innerHTML = oText;
                this.overview.style.display = "block";

                this.formSchoolInvoice.style.display = "block";


                oCart.updateShoppingSummary();
            }
        };

        CartForm.prototype.validateStep1 = function () {
            var reNumbersOnly = /^[0-9]+$/;
            var reEmail = /\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/;

            var fFirstname = document.forms['SubmitOrder'].Firstname.value;
            var fLastname = document.forms['SubmitOrder'].Lastname.value;
            var fOrganisation = document.forms['SubmitOrder'].Organisation.value;
            var fPostalAddress = document.forms['SubmitOrder'].PostalAddress.value;
            var fPostalCity = document.forms['SubmitOrder'].PostalCity.value;
            var fAddressType = getAddressType();

            var regExpPOBox = /(\b)(po|p o|pb|p.o|box|bag|locked|private|locked bag|ms|rmd|private bag)(\b)/;
            if (fPostalAddress && regExpPOBox.test(fPostalAddress.toLowerCase())) {
                alert('Sorry, we do not deliver to post office/private boxes.');
                return false;
            }

            if (document.forms['SubmitOrder'].PostalState.selectedIndex != 0) {
                var fPostalState = document.forms['SubmitOrder'].PostalState.getElementsByTagName('option')[document.forms['SubmitOrder'].PostalState.selectedIndex].value;
            } else {
                var fPostalState = "";
            }
            var fPostalCode = document.forms['SubmitOrder'].PostalCode.value;

            var oOrder = document.forms['SubmitOrder'].overseasOrder;
            for (var i = 0; i < oOrder.length; i++) {
                if (oOrder[i].checked) var fOverseasOrder = oOrder[i].value;
            }


            var fPhoneNumber = document.forms['SubmitOrder'].PhoneNumber.value;
            var fEmailAddress = document.forms['SubmitOrder'].EmailAddress.value;

            var oText = "Please fill in or verify the following field(s):\n";
            if (fFirstname == "" || fFirstname == " ") oText += "-Firstname\n";
            if (fLastname == "" || fLastname == " ") oText += "-Lastname\n";
            if (this.payType == "4" || this.payType == "3" || fAddressType == '2') {
                if (fOrganisation == "" || fOrganisation == " ") oText += "-School/University name\n";
            }
            if (fAddressType == "") oText += "-Address Type (private or school/institution)\n";
            if (fPostalAddress == "" || fPostalAddress == " ") oText += "-Street address\n";
            if (fPostalCity == "" || fPostalCity == " ") oText += "-Suburb\n";
            if ((fPostalState == "" || fPostalState == " ") && fOverseasOrder == "0") oText += "-State\n";

            if (!reNumbersOnly.test(fPostalCode) || fPostalCode.length < 4 || fPostalCode.length > 10 || (fOverseasOrder == "0" && fPostalCode.length > 4)) oText += "-Postal code (numbers only)\n";
            if (!reNumbersOnly.test(fPhoneNumber) || fPhoneNumber.length < 8) oText += "-Phone number (numbers only)\n";
            if (!reEmail.test(fEmailAddress) || fEmailAddress == "" || fEmailAddress == " ") oText += "-Email address\n";

            if (oText != "Please fill in or verify the following field(s):\n") {
                alert(oText);
                return false;
            }

            return true;
        };

        CartForm.prototype.validateCreditCard = function () {
            var fCardName = document.forms['SubmitOrder'].CardName.value;
            var fCardNumber = document.forms['SubmitOrder'].CardNumber.value;
            var fCardMonth = document.forms['SubmitOrder'].CardMonth.value;
            var fCardYear = document.forms['SubmitOrder'].CardYear.value;

            var oText = "Please fill in the following field(s):\n";
            if (fCardName == "" || fCardName == " ") oText += "-Card holder name\n";
            if (fCardNumber == "" || fCardNumber == " ") oText += "-Card number\n";
            if (fCardMonth == "MM" || fCardMonth == "" || fCardYear == "YY" || fCardYear == "") oText += "-Card expiry date\n";

            if (oText != "Please fill in the following field(s):\n") {
                alert(oText);
                return false;
            }

            var reCardNumber = /\d{16}/;
            if (!reCardNumber.test(fCardNumber)) {
                alert("Please enter a valid credit card number.");
                return false;
            }

            var reYear = /\d{2}/;
            var reMonth = /0[1-9]|1[0-2]/;
            if ((!reMonth.test(fCardMonth)) || (!reYear.test(fCardYear))) {
                alert("Please enter a valid expiry date.");
                return false;
            }

            return true;

        };

        CartForm.prototype.validateInvoice = function () {
            var fOrderNumber = document.forms['SubmitOrder'].Inv_Order_Number.value;
            var fAccountCode = document.forms['SubmitOrder'].Inv_Order_AccountCode.value;

            var oText = "Please fill in the following field(s):\n";
            if (fOrderNumber == "" || fOrderNumber == " ") oText += "-Customer order number\n";

            if (oText != "Please fill in the following field(s):\n") {
                alert(oText);
                return false;
            }

            return true;
        };

        CartForm.prototype.getDeliverySummary = function () {
            var oText = '<p class="deliverySummary"><span>Your delivery details:</span><br /><br />';
            oText += document.forms['SubmitOrder'].Firstname.value + " " + document.forms['SubmitOrder'].Lastname.value + "<br />";
            if (document.forms['SubmitOrder'].Organisation.value != "") {
                oText += document.forms['SubmitOrder'].Organisation.value + "<br />";
            }
            oText += document.forms['SubmitOrder'].PostalAddress.value + "<br />";
            oText += document.forms['SubmitOrder'].PostalCity.value + " " + document.forms['SubmitOrder'].PostalState.value + " " + document.forms['SubmitOrder'].PostalCode.value;
            oText += "</p>";
            return oText;
        };

        CartForm.prototype.getPaymentSummary = function () {
            var oText = '<p class="paymentSummary"><span>Your payment information:</span><br /><br />';
            if (this.payType == "2" || this.payType == "3") {
                var nCard = "xxxx xxxx xxxx " + document.forms['SubmitOrder'].CardNumber.value.substring(12);
                oText += "Your ";
                if (this.payType == "3") oText += " school ";
                oText += document.forms['SubmitOrder'].CardType.value + " fcredit card ending in ";
                oText += nCard + " will be charged.<br /><br />";
            }
            if (this.payType == "3" || this.payType == "4") {
                oText += "Customer Order Number: " + document.forms['SubmitOrder'].Inv_Order_Number.value + ".<br /><br />";
                oText += "Account Code: " + document.forms['SubmitOrder'].Inv_Order_AccountCode.value + ".<br /><br />";
                oText += "On verification by our Customer Service department the transaction will be processed.<br /><br />";
            }
            return oText;
        };
    }
    CartForm._initialized = true;
}

function getAddressType() {
    var fAddressType = '';
    var fAddressTypeRadio = document.forms['SubmitOrder'].AddressType;

    for (var i = 0; i < fAddressTypeRadio.length; i++) {
        if (fAddressTypeRadio[i].checked) fAddressType = fAddressTypeRadio[i].value;
    }
    return fAddressType;
}