CODE EXAMPLE FOR JAVASCRIPT

ajax onchange dropdown

jQuery(document).ready(function($) {
    $("#opt_level").on('change', function() {
        var level = $(this).val();
        if(level){
            $.ajax ({
                type: 'POST',
                url: 'example-domain.com',
                data: { hps_level: '' + level + '' },
                success : function(htmlresponse) {
                    $('#opt_lesson_list').html(htmlresponse);
                    console.log(htmlresponse);
                }
            });
        }
    });
});