Access the file system in Windows Phone using PhoneGap

I am new to Windows Phone (using PhoneGap). Where will the created file be saved when we write the file using PhoneGap? I also need to get the memory path on the phone.

 document.addEventListener("deviceready",onDeviceReady,false);    
    function onDeviceReady() {
        navigator.notification.alert("Device Ready");
        window.requestFileSystem(LocalFileSystem.APPLICATION, 0, gotFS, fail);
    }
    function gotFS(fileSystem) {
        fileSystem.root.getFile("TextFile3.txt", {create: true, exclusive: false}, gotFileEntry, fail);
        navigator.notification.alert("gotFS");
    }
    function gotFileEntry(fileEntry) {
        fileEntry.createWriter(gotFileWriter, fail);
        navigator.notification.alert("gotFileEntry");
    }
    function gotFileWriter(writer) {
        navigator.notification.alert("gotFileWriter");
        writer.onwriteend = function (evt) {
            console.log("contents of file now 'some sample text'");
            writer.truncate(11);
            writer.onwriteend = function (evt) {
                console.log("contents of file now 'some sample'");
                writer.seek(4);
                writer.write(" different text");
                writer.onwriteend = function (evt) {
                    console.log("contents of file now 'some different text'");
                    navigator.notification.alert("gotFileWriterEnd");
                }
            };
        };
        writer.write("some sample text");

    }
    function fail(error) {
        console.log(error.code);
    }