Konversi Rupiah ke Dollar (Java)

/*
nama file : RupiahkeDollar.java
programer : elekomfireball.blogspot.com
deskripsi :
 -input Nilai Rupiah
 -tampilkan hasil konversi Rupiah ke Dollar
*/
import javax.swing.JOptionPane;
class RupiahkeDollar 
{
 public static void main(String[] args) 
 {
  String RupiahString;
  Double rupiah;
  Double Dollar;
  
  RupiahString = JOptionPane.showInputDialog("Masukkan Nilai Rupiah : ");
  rupiah = Double.parseDouble(RupiahString);

  Dollar = rupiah / 9000;
  
  JOptionPane.showMessageDialog(null,"Dollar : \n" + Dollar);
 }
}