Prevent submission if number of availability in stock is less than requested item quantity

[profile]

Implement Server-Side (Back-End) Validations:

· Stock Availability Check:

o Before the form is submitted, check if the selected Model is available in the stock. If the stock is insufficient, prevent submission and display an appropriate error message.
I am trying with this script which is not working. Please can any one able to correct it or give me a correct code:
Script Include Code:

var CheckStockAvailability = Class.create();

CheckStockAvailability.prototype = Object.extendsObject(AbstractAjaxProcessor, {

    checkStock: function() {

        var model = this.getParameter('sysparm_model');

        var qty = parseInt(this.getParameter('sysparm_quantity1'), 10); // Use quantity1, base 10

        // Validate quantity

        if (isNaN(qty) || qty < 1 || qty > 5) {

            return 'Invalid quantity. Must be between 1 and 5';

        }

        var gr = new GlideRecord('alm_asset');

        gr.addQuery('display_name', model);

        gr.query();

        if (gr.next()) {

            var available = parseInt(gr.getValue('quantity'), 10); // Check against out-of-box quantity field

            if (available >= qty) {

                return 'OK';

            } else {

                return 'Only ' + available + ' items available for model ' + model;

            }

        }

        return 'Model not found in stock';

    },

    type: 'CheckStockAvailability'

});

Catalog Client Script code:

function onSubmit() {

    var model = g_form.getValue('model');

    var quantity = parseInt(g_form.getValue('quantity1'), 10); // Use quantity1 field

    // Client-side validation

    if (isNaN(quantity) || quantity < 1 || quantity > 5) {

        g_form.showFieldMsg('quantity1', 'Quantity must be between 1 and 5', 'error');

        return false;

    }

    var ga = new GlideAjax('CheckStockAvailability');

    ga.addParam('sysparm_name', 'checkStock');

    ga.addParam('sysparm_model', model);

    ga.addParam('sysparm_quantity1', quantity); // Pass quantity1

    ga.getXML(function(response) {

        var answer = response.responseXML.documentElement.getAttribute('answer');

        if (answer !== 'OK') {

            g_form.showFieldMsg('quantity1', answer, 'error');

            g_form.setSubmit(false); // Prevent form submission

        } else {

            g_form.setSubmit(true); // Allow form submission

        }

    });

    return false; // Prevent default submission until Ajax completes

}

[palanikumar]

There is a typo in one condition operator

Replace

        if (answer !== 'OK') {

with

        if (answer != 'OK') {