How do I use jQuery to load my advertisements?

Question

Some ads on my website are slowing down load time. How can I use jquery to load the ad code while the page is loading?

I tried something like this:

$(document).ready(function () {
    advertisement();

    function advertisement() {
        $.ajax({
            type: "GET",
            url: "/advertisement.php",
            data: "type=googleads",
            beforeSend: function () {
                $("#advertisement").html('Loading ...');
            },
            cache: false,
            success: function (a) {
                $("#advertisement").html(a);
            }
        });
    }
});

But it redirects me to the ads company site instead of showing the ads.

Is it possible?