private void btnBayarActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
bayar = Double.parseDouble(txtBayar.getText());
cash1 = Double.parseDouble(txtCash.getText());
sisa = cash1 - bayar;
sisa1 =Double.toString(sisa);
txtSisa.setText("Rp. "+sisa1);
}