(Information and examples taken from the DroidScript documentation)

The GetExternalFolder method returns the full path of the external storage (in early versions of Android, this is often a removable sdcard).

In some phones(e.g my phone) it returns the full path of the internal storage.

 app.GetExternalFolder();

function OnStart()
{
  fldr = app.GetExternalFolder();
  app.ShowPopup( fldr );
}