Add this permission in Manifest,
File folder = new File(Environment.getExternalStorageDirectory() +
File.separator + "TollCulator");
boolean success = true;
if (!folder.exists()) {
success = folder.mkdirs();
}
if (success) {
// Do something on success
} else {
// Do something else on failure
}
when u run the application go too DDMS->File Explorer->mnt
folder->sdcard folder->toll-creation folder