Using File Transfer Plugin in Phonegap Application

I have more than 2 weeks that i tried to download file PDF in phonegap application using the File Transfer Plugin but it didn't work!! i make everything for that:

-installing the last version of phonegap

-installing the last version of File Transfer plugin

And this is the code to integrate in Javascript interface:

var fileTransfer = new FileTransfer();
fileTransfer.download("http://developer.android.com/assets/images/home/ics-android.png", "file://sdcard/ics-android.png", 
function (entry) {
    alert("download complete: " + entry.fullPath);
}, function (error) {
    alert("download error source " + error.source);
    alert("download error target " + error.target);
    alert("upload error code" + error.code);
});

But it seems wrong!!! I have like a result last three alerts in an android device:

-Download error source

-Download error target

-Upload error code

What i should doing?!!

Message was edited by: Kerri Shotts; code syntax highlighted and indented for clarity