How to download to an sd card in AIR - air

Question

I have a download function that I got from Andy Matthews, and an sd Card function that I got from Christian Cantrell. Now I need to download to the sd Card.
Q: How do I specify that storage = e.storageVolume.rootDirectory.nativePath?
var remoteFile = 'http://www.CompanyName.com/ClientName.txt';
jQuery(function($){
air.StorageVolumeInfo.storageVolumeInfo.addEventListener(air.StorageVolumeChangeEvent.STORAGE_VOLUME_MOUNT, onVolumeMount);
air.StorageVolumeInfo.storageVolumeInfo.addEventListener(air.StorageVolumeChangeEvent.STORAGE_VOLUME_UNMOUNT, onVolumeUnmount);
var PluggedIn = false;
var volumes = air.StorageVolumeInfo.storageVolumeInfo.getStorageVolumes();
for (var i = 0; i < volumes.length; i++) {
if (volumes[i].isRemovable) {
if (volumes[i].name == 'COMPANYNAME') {
PluggedIn = true;
$('#content').append('I see you already have CompanyName plugged in!');
var myNativePath = volumes[i].rootDirectory.nativePath;
var storage = 'desktopDirectory'; // myNativePath
downloadFile(remoteFile, storage);
} else {
$('#content').append('What you have plugged in is not CompanyName.');
}
}
}
if (!PluggedIn){
$('#content').append('<h1>Please insert your CompanyName card.</h1>');
}
})
function onVolumeMount(e) {
if (e.storageVolume.isRemovable) {
$('#content').html('<h1>Thank you</h1>');
if (e.storageVolume.name == 'COMPANYNAME') {
var myNativePath = e.storageVolume.rootDirectory.nativePath;
var storage = 'desktopDirectory'; // myNativePath
downloadFile(remoteFile, storage);
} else {
$('#content').append('<p>The card you just plugged in is not CompanyName.</p>');
}
} else {
$('#content').append('<p>This device is not removable</p>');
}
}
function onVolumeUnmount(e) {
$('#content').html('<h1>Goodbye!</h1>');
}
function downloadFile(remoteFile, storage){
var fn = remoteFile.match(/[a-z0-9-+\._]+?$/i);
var myFile = air.File[storage].resolvePath(fn);
var myURLStream = new air.URLStream();
myURLStream.addEventListener(air.Event.COMPLETE, function(e){
var myByteArray = new air.ByteArray();
myURLStream.readBytes(myByteArray, 0, myURLStream.bytesAvailable);
var myFileStream = new air.FileStream();
myFileStream.openAsync(myFile, air.FileMode.WRITE);
myFileStream.writeBytes(myByteArray, 0);
myFileStream.close();
});
myURLStream.load(new air.URLRequest(remoteFile));
}

Answer 1

var myFile = new air.File("file:///" + storage).resolvePath(fn);