private void validateColourPrint() {
        
        //colour printing validation
        Enumeration<AbstractButton> colours = colour.getElements();
        boolean selected = false;
        String colourPrinting = "";
        int i=0;
        while (colours.hasMoreElements() && i<3) {
            i++;
            AbstractButton checkbox = colours.nextElement();
            if(checkbox.isSelected())
            {
                colourPrinting = checkbox.getText();
                if("None".equals(colourPrinting))
                {
                    colourPrinting = "0";
                }
                selected = true;
                colourPrint = Integer.parseInt(colourPrinting);
                if(!"".equals(colourPrintError.getText()))
                {
                    colourPrintError.setText("");
                }
                break;
            }

        }
        if(selected == false)
        {
            colourPrintError.setText("*you need to select a colour printing !");
        }
      
    }