c#

[Nestory]

 private void button1_Click(object sender, EventArgs e)
        {
            SalesTransaction s1 = new SalesTransaction(0.06);
            listBox1.Items.Add(s1.ToString());
            SalesTransaction s2 = new SalesTransaction("John Doe: ", 170000, 0.07); // 11900
           // s2.SalesAmount = 210000;
           //The commission should be automatically adjusted. 14700
            listBox1.Items.Add(s2.ToString());
            SalesTransaction s3 = new SalesTransaction("Jane Doe: ", 200000); // 0
            listBox1.Items.Add(s3.ToString());
            SalesTransaction s4 = new SalesTransaction("Tim Doe: "); // 0
            listBox1.Items.Add(s4.ToString());
            SalesTransaction s5 = s2 + s2;
            listBox1.Items.Add(s5.ToString());
        }
    }

    class SalesTransaction
    {
        private readonly double commissionRate; // page 386
        private decimal commission; // this is a calculated field
        public string Salesperson { get; set; } // auto-implemented property
        public decimal SalesAmount { get; set; }

        public double CommissionRate
        {
            get
            {
                return commissionRate;
            }
        }
        public decimal Commission
        {
            get
            {
                double salesNumber = Convert.ToDouble(SalesAmount);
                return commission = Convert.ToDecimal(salesNumber * commissionRate);
            }
        }
        public SalesTransaction(double rate)
        {
            commissionRate = rate;
        }
        public SalesTransaction(string disName, double Commie1, double rate)
        {
            commissionRate = rate;
            Salesperson = disName;
            SalesAmount = (decimal)Commie1;
        }
        (I have tried to finish this but im stuck here help me please)

[hericles]

What exactly are you stuck on? You haven't told us what you're trying to do.

[Nutster]

When you are providing extra information for an existing question, it is better to reply to your original question, rather than creating a new question.

[Nutster]

In general, a constructor should set all applicable data members, even if not provided in the constructor arguments. Before using a list box to display something, it might be a good idea to clear the list box of any previous strings.
listbox1.clear();