JSFiddle - React, Tailwind, and code Playground

HTML

<form id="my_form">
    Name: <input type="text" id="name" size="20" />
    <br />Country: <input type="text" id="country" size="20" />
    <br />Email: <input type="text" id="email" size="20" />
    <br />Department: <input type="text" id="dept" size="20" />
    <br /><input type="submit" id="submit" value="Login" />
</form>

JavaScript

$(document).ready(function() {
    
    $('#my_form').submit(function() {
        
        var name = $('#name').val();
        var country = $('#country').val();
        var email = $('#email').val();
        var dept = $('#dept').val();

        /* Validate everything */
        if (name != '' && country != '' && email != '' && dept != '') {

            /* Validation succeeded. Do whatever. */
            
        }

        else {

            alert('Validation failed.');
        }

        return false;
    });

});