classList.add(hiClass);

}

var buildAmountData = function(amountInput) {

    var amountData = {

        minAmount: parseFloat(amountInput.min),

        newAmount: parseFloat(amountInput.value),

    }

    if (amountInput.dataset.oldAmount !== undefined) {

        amountData.oldAmount = parseFloat(amountInput.dataset.oldAmount);

    }

    return amountData;

}

var supportTypeSelector = function(supportTypeHash) {

    return $(supportTypeHash + "Selector");

};

/* We've sometimes published links that say #renew instead of #renewal.

Rewrite that to work as intended. */

if (window.location.hash === "#renew") {

    window.location.hash = "#renewal";

}

function init_sustainer_form_validation () {

    // Forms start in "invalid" form, with the errors shown, so that

    // non-Javascript users see the errors by default and know what they must

    // enter.  Now we hide those for JavaScript users:

    $formCorrectionNeeded.addClass('hidden');

    $('form.supporter-form').each(function(index, form) {

        var $amountInput = $('input[type=number]', form).first();

        var $amountError = $('.form-error', $amountInput.parents('.supporter-form-input'));

        $amountError.on(NEW_AMOUNT_EVENT, function(event, amountData) {

            var isValid = amountData.newAmount >= amountData.minAmount;

            if (amountData.oldAmount === undefined) {

                if (isValid) {

                    $amountError.addClass('hidden');

                } else {

                    flipClass($amountInput[0], 'valid', 'invalid');

                    $amountError.removeClass('hidden');

                }

            } else if (isValid) {

                flipClass($amountInput[0], 'invalid', 'valid');

                $amountError.fadeOut();

            } else if (amountData.oldAmount >= amountData.minAmount) {

                flipClass($amountInput[0], 'valid', 'invalid');

                $amountError.fadeIn();

            }

        });