var localServer = "http://www.mstechday.com/xml/Tweets.aspx";

//função inicial
$(document).ready(function () {
    changediv();
})

function geturl(addr) {
    var r = $.ajax({
        type: 'GET',
        url: addr,
        async: false
    }).responseText;

    return r;
}

function changediv() {
    $('#tweets').html(geturl(localServer));
}