function get_current_url() {
   $url = isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? "https" : "http";
   $url .= isset($_SERVER['HTTP_HOST']) ? "://" . $_SERVER['HTTP_HOST'] : null;
   $url .= isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : null;
   return $url;
}

$(document).ready(function(){
    $("#user_search").on("input", function(){
        var query = $(this).val();
        if (query.length > 0) {
            $.ajax({
                url: '<?=get_current_url();?>',
                type: "POST",
                data: { query: query },
                success: function(data){
                    $("#userList").fadeIn();
                    $("#userList").html(data);
                }
            });
        } else {
            $("#userList").fadeOut();
            $("#userList").html("");
        }
    });
    $(document).on("click", "option", function(){
        $("#user_search").val($(this).text());
        $("#user_id").val($(this).data("id"));
        $("#userList").fadeOut();
    });
});