function fileDownload(dirName, fileURL, fileName) {

    window.requestFileSystem = window.requestFileSystem || window.webkitRequestFileSystem;

    window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, fsAccess, fsFail);

    function fsAccess(fileSystem) {

        fileSystem.root.getDirectory(dirName, { create: true, exclusive: false }, dirReady, dirFail);

    }

    function fsFail() {

        console.log("Filesystem Access Failed");

    }

    function dirFail() {

        console.log("Directory Access Failed");

    }

    function dirReady(entry) {

        window.appRootDir = entry;

        console.log(JSON.stringify(window.appRootDir));

        var fileTransfer = new FileTransfer();

        fileTransfer.download(
            fileURL,
            window.appRootDir.nativeURL + fileName,
            function (theFile) {
                console.log("download complete: " + theFile.toURL());
            },
            function (error) {
                console.log(JSON.stringify(error));
            }
        );

    }

}