loadVars.send() post or get

My question is that when I use the code

    var submitPoints = new LoadVars();
    submitPoints.user = "Aaron";
    submitPoints.pointsArray = _parent.pointsArray;
    submitPoints.send("http://testing.tldstudio.com/misctests/whiteBoarding/submit.php",  "_blank", "POST");

when i submit this… the array that I am reading in… get read into the URL. Why is it going into the URL? I use the POST method so shouldn’t it now go throught the URL? The reason I ask… is because if the array gets too big when you try to submit, the server rejects it because the url is too large.
Any ideas on how to fix?