SwitchSsss

private void cbshitActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
        String stype = cbshit.getSelectedItem().toString();//declaring it in a variable so it will be easy to call this shit
        double TF = Double.parseDouble(otf.getText());
        double LF = Double.parseDouble(olf.getText());
        double MF = Double.parseDouble(omf.getText());
        double EF = Double.parseDouble(oef.getText());
        double MandanasDiscount[] = {(TF - (TF / 100 * 20)),(LF - (LF / 100 * 20)),(MF - (MF / 100 * 20)),(EF - (EF / 100 * 20))};
        double VilmaDiscount[] = {(TF - (TF / 100 * 15)),(LF - (LF / 100 * 15)),(MF - (MF / 100 * 15)),(EF - (EF / 100 * 15))};
        double PGSDiscount[] = {(TF - (TF / 100 * 10)),(LF - (LF / 100 * 10)),(MF - (MF / 100 * 10)),(EF - (EF / 100 * 10))};
        double SFWDiscount[] = {(TF - (TF / 100 * 5)),(LF - (LF / 100 * 5)),(MF - (MF / 100 * 5)),(EF - (EF / 100 * 5))};
        switch(stype)
        {
            case "Mandanas":
                if(otf.getText() != "")
                {
                    if(TF > 0)
                    {
                        ftf.setText("" + MandanasDiscount[0]);
                    }
                    else if(TF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        ftf.setText("" + TF);
                    }
                }
                if(olf.getText() != "")
                {
                    if(LF > 0)
                    {
                        flf.setText("" + MandanasDiscount[1]);
                    }
                    else if(LF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        flf.setText("" + LF);
                    }
                }
                if(omf.getText() != "")
                {
                    if(MF > 0)
                    {
                        fmf.setText("" + MandanasDiscount[2]);
                    }
                    else if(MF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fmf.setText("" + MF);
                    }
                }
                if(oef.getText() != "")
                {
                    if(EF > 0)
                    {
                        fef.setText("" + MandanasDiscount[3]);
                    }
                    else if(EF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fef.setText("" + EF);
                    }
                }
                break;
            case "Vilma":
                if(otf.getText() != "")
                {
                    if(TF > 0)
                    {
                        ftf.setText("" + VilmaDiscount[0]);
                    }
                    else if(TF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        ftf.setText("" + TF);
                    }
                }
                if(olf.getText() != "")
                {
                    if(LF > 0)
                    {
                        flf.setText("" + VilmaDiscount[1]);
                    }
                    else if(LF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        flf.setText("" + LF);
                    }
                }
                if(omf.getText() != "")
                {
                    if(MF > 0)
                    {
                        fmf.setText("" + VilmaDiscount[2]);
                    }
                    else if(MF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fmf.setText("" + MF);
                    }
                }
                if(oef.getText() != "")
                {
                    if(EF > 0)
                    {
                        fef.setText("" + VilmaDiscount[3]);
                    }
                    else if(EF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fef.setText("" + EF);
                    }
                }
                break;
            case "PGS":
                if(otf.getText() != "")
                {
                    if(TF > 0)
                    {
                        ftf.setText("" + PGSDiscount[0]);
                    }
                    else if(TF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        ftf.setText("" + TF);
                    }
                }
                if(olf.getText() != "")
                {
                    if(LF > 0)
                    {
                        flf.setText("" + PGSDiscount[1]);
                    }
                    else if(LF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        flf.setText("" + LF);
                    }
                }
                if(omf.getText() != "")
                {
                    if(MF > 0)
                    {
                        fmf.setText("" + PGSDiscount[2]);
                    }
                    else if(MF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fmf.setText("" + MF);
                    }
                }
                if(oef.getText() != "")
                {
                    if(EF > 0)
                    {
                        fef.setText("" + PGSDiscount[3]);
                    }
                    else if(EF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fef.setText("" + EF);
                    }
                }
                break;
            case "SFW":
                if(otf.getText() != "")
                {
                    if(TF > 0)
                    {
                        ftf.setText("" + SFWDiscount[0]);
                    }
                    else if(TF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        ftf.setText("" + TF);
                    }
                }
                if(olf.getText() != "")
                {
                    if(LF > 0)
                    {
                        flf.setText("" + SFWDiscount[1]);
                    }
                    else if(LF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        flf.setText("" + LF);
                    }
                }
                if(omf.getText() != "")
                {
                    if(MF > 0)
                    {
                        fmf.setText("" + SFWDiscount[2]);
                    }
                    else if(MF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fmf.setText("" + MF);
                    }
                }
                if(oef.getText() != "")
                {
                    if(EF > 0)
                    {
                        fef.setText("" + SFWDiscount[3]);
                    }
                    else if(EF < 0)
                    {
                        JOptionPane.showMessageDialog(null,"You are not allow to input negative values","Error",WIDTH);
                    }
                    else
                    {
                        fef.setText("" + EF);
                    }
                }
                break;
            default:
                ftf.setText("" + TF);
                flf.setText("" + LF);
                fmf.setText("" + MF);
                fef.setText("" + EF);
                break;

        }
    }