This script can be used to apply a discount on a selected item.

Administrator Menu > Maintenance > Resources
Create a resource Script.DiscountOnItem and copy paste below code:

pflag = 0;
if (sales.getSelectedIndex() >= 0) {
 String discountperc = JOptionPane.showInputDialog(null, "Please enter discount amount:n(Add a % sign at the end for percentage discount.)");
 if (discountperc.length() > 0) {
  double discountrate = 0.0;
  if (discountperc.lastIndexOf("%") == discountperc.length() - 1 && Double.parseDouble(discountperc.substring(0, discountperc.lastIndexOf("%"))) > 0.0) {
   discountrate = Double.parseDouble(discountperc.substring(0, discountperc.lastIndexOf("%")));
   discountrate = discountrate / 100.00;
   pflag = 1;
  } else if (Double.parseDouble(discountperc) > 0.0) {
   discountrate = Double.parseDouble(discountperc);
  }

  line = ticket.getLine(sales.getSelectedIndex());

  if (pflag == 1) {
   line.setSalePrice(line.getPrice() - (line.getPrice() * discountrate * 1));
  } else {
   line.setSalePrice(line.getPrice() - discountrate);
  }
 }
} else {
 java.awt.Toolkit.getDefaultToolkit().beep();
}

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