php - javascript変数でphp関数の戻り値を取得する方法

Question

returnPHP 関数の値を JavaScript 変数に使用するにはどうすればよいですか? 例：

PHP:

// Destination folder for downloaded files

$date = date('m.d.y'); 
mkdir("uploads/" . $date, 0777, true); 
$upload_folder = 'uploads/' . $date;

// If the browser supports sendAsBinary () can use the array $ _FILES
if(count($_FILES)>0) { 
    if( move_uploaded_file( $_FILES['upload']['tmp_name'] , $upload_folder.'/'.$_FILES['upload']['name'] ) ) {
        echo 'done';
    }
    exit();
} else if(isset($_GET['up'])) {
    // If the browser does not support sendAsBinary ()
    if(isset($_GET['base64'])) {
        $content = base64_decode(file_get_contents('php://input'));
    } else {
        $content = file_get_contents('php://input');
    }

    $headers = getallheaders();
    $headers = array_change_key_case($headers, CASE_UPPER);

    if(file_put_contents($upload_folder.'/'.$headers['UP-FILENAME'], $content)) {
        echo 'done';
    }
    exit();
}

$pathinfo = realpath($upload_folder);
return $pathinfo;

Javascript

this.MakeRequest = function()
{
  var somename = "somenameTest";
  var xmlHttp = getXMLHttp();

  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      HandleResponse(xmlHttp.responseText);
    }
  }

  xmlHttp.open("GET", "download.php", true); 
  xmlHttp.send();
}

function HandleResponse(response)
{
  document.getElementById('output').innerHTML = response;
      **var x = php return varible**

}