$.ajax({
    type: "POST",
    url: "/management/uploadFile",
    dataType: "JSON",
    data: "uploadedFile="+uploadedFile,
    cache: false,
    success:
    function(data){
        $('#mydiv').html(change_html(data));
    },
});

function change_html(data)
{
    var html;

    html += '<div id="mydiv">';
    html += 'Hello World !<br/>';
    html += '</div>';
    return html;
}