if(serialPort1.BytesToRead > 0)
            {
                string color = serialPort1.ReadLine().Trim();
                if(color.StartsWith("WHITE"))
                {
                    double wprice = 5;
                    Balance[names.IndexOf(tbBuyer.Text)] -= wprice;
                    lbx1.Items.Clear();
                    foreach (string mate in names)
                    {
                        lbx1.Items.Add(mate + "\t" + Balance[names.IndexOf(mate)].ToString("0.00€"));
                    }
                }
               else if (color.StartsWith("BLACK"))
                {
                    double bprice = 2;
                    Balance[names.IndexOf(tbBuyer.Text)] -= bprice;
                    lbx1.Items.Clear();
                    foreach (string mate in names)
                    {
                        lbx1.Items.Add(mate + "\t" + Balance[names.IndexOf(mate)].ToString("0.00€"));
                    }
                }
                else if (color.StartsWith("RED"))
                {
                    double rprice = 3;
                    Balance[names.IndexOf(tbBuyer.Text)] -= rprice;
                    lbx1.Items.Clear();
                    foreach (string mate in names)
                    {
                        lbx1.Items.Add(mate + "\t" + Balance[names.IndexOf(mate)].ToString("0.00€"));
                    }
                }
                else if (color.StartsWith("BLUE"))
                {
                    double blprice = 4;
                    Balance[names.IndexOf(tbBuyer.Text)] -= blprice;
                    lbx1.Items.Clear();
                    foreach (string mate in names)
                    {
                        lbx1.Items.Add(mate + "\t" + Balance[names.IndexOf(mate)].ToString("0.00€"));
                    }
                }
                else if (color.StartsWith("GREEN"))
                {
                    double gprice = 1;
                    Balance[names.IndexOf(tbBuyer.Text)] -= gprice;
                    lbx1.Items.Clear();
                    foreach (string mate in names)
                    {
                        lbx1.Items.Add(mate + "\t" + Balance[names.IndexOf(mate)].ToString("0.00€"));
                    }
                }