function InvokePaymentRequestHandler() {
    $(document).ready(function () {
        var $invoiceNumberField = $("#t3_invoicenumber");
        var $amountField = $("#t3_amount");
        var $submitButton = $(".submit-btn");

        //ValidateInvoiceNumber(); // 2023-05-30: Since the GMS portal upgrade the invoice number validation is not implemented
        ValidateTotalAmount();
        //ProcessTotals();

        //function ProcessTotals() {
        //    // 2023-05-30: As of CR1020 the invoice form has no line item grid. This function is deprecated.
        //    // adds event listener to the invoice detail table
        //    // to recalculate the total amount
        //    $(".entity-grid.subgrid").on("loaded", function () {
        //        var total = 0;
        //        $("[data-attribute='t3_amount']").each(function (index, value) {
        //            var amt = $(value).text().replace("$", "").replace(/,/g, "");
        //            total += parseFloat(amt);
        //        });

        //        $amountField.val(TransformIntoCurrencyFormat(total));
        //        $amountField.siblings(".text-muted").hide(); // fixes a display styling issue

        //        // disables next button if total if below 1
        //        if (total < 1) {
        //            $submitButton.attr("disabled", 1);
        //        }
        //        else {
        //            ValidateInvoiceAmount(total);
        //        }
        //    });
        //}

        function ValidateInvoiceNumber() {
            // save original invoice number value on form load
            var originalInvoiceNumber = $invoiceNumberField.val();

            // adds event listener to invoice number field change
            // validates for duplicate invoice numbers
            $invoiceNumberField.keyup(function () {

                var invoiceNumberEntered = $(this).val();
                if (invoiceNumberEntered == originalInvoiceNumber) {
                    return;
                }

                var data = { "Id": GetRequestId(), "InvoiceNumber": $(this).val() };
                $.post("/_services/GMS/PaymentRequest/InvoiceNumber", data).done(function (response) {
                    console.debug("dup invoice number? " + response);
                    if (response === true) {
                        if ($("#dupInvoiceWarning").length < 1) {
                            // message doesn't already exist
                            var errMessage = "<p id='dupInvoiceWarning' class='text-danger'>This invoice number has already been submitted by your organization. Please enter a different invoice number.</p>";
                            $invoiceNumberField.closest("td").append();
                        }
                        $(".btn").prop("disabled", true);
                    }
                    else {
                        $("#dupInvoiceWarning").remove();
                        $(".btn").prop("disabled", false);
                    }
                });
            });
        }

        //function ValidateInvoiceAmount(amt) {
        //    var paymentRequestId = $("#EntityFormView_EntityID").val();

        //    if (paymentRequestId == null || paymentRequestId.length < 1) {
        //        paymentRequestId = $("#EntityFormControl_EntityFormView_EntityID").val();
        //    }

        //    $.getJSON("/API/ConsultantRequestBalance/?id=" + GetRequestId()).done(function (response) {
        //        if (response.Balance === 'undefined' || response.Balance < 0 || amt > parseFloat(response.Balance)) {
        //            if ($("#invalidAmountWarning").length < 1) {
        //                // invalid amount message doesn't already exist, add it
        //                var errMessage = "<p id='invalidAmountWarning' class='text-danger'>The amount is invalid. This may be due to an amount exceeding your available amount. Please review and try again.</p>";
        //                $amountField.closest("td").append(errMessage);
        //            }
        //            $submitButton.prop("disabled", true);
        //        }
        //        else {
        //            $("#invalidAmountWarning").remove();
        //            $submitButton.prop("disabled", false);
        //        }
        //    });
        //}

        function ValidateTotalAmount() {

            // on first load 
            Validate();

            // on subsequent field changes
            $amountField.on("keyup", Validate);

            function Validate() {
                var amount = parseFloat($amountField.val().replace("$", "").replace(/,/g, ""));

                if (isNaN(amount) || amount < 1) {
                    $submitButton.attr("disabled", 1);
                }
                else {
                    $.getJSON("/API/ConsultantRequestBalance/?id=" + GetRequestId()).done(function (response) {
                        if (response.Balance === 'undefined' || response.Balance < 0 || amount > parseFloat(response.Balance)) {
                            if ($("#invalidAmountWarning").length < 1) {
                                // invalid amount message doesn't already exist, add it
                                var errMessage = "<p id='invalidAmountWarning' class='text-danger'>The amount is invalid. This may be due to an amount exceeding your available amount. Please review and try again.</p>";
                                $amountField.closest("td").append(errMessage);
                            }
                            $submitButton.prop("disabled", true);
                        }
                        else {
                            $("#invalidAmountWarning").remove();
                            $submitButton.prop("disabled", false);
                        }
                    });
                }
            }
        }

        function GetRequestId() {
            var urlParams = new URLSearchParams(window.location.search);
            var projectId = urlParams.get('refid');
            return projectId;
        }
    });

}