title: System.FormatException in C#
body: <p>I keep getting a FormatException in each of the cases on the line where I try to assign the value for the sale variable. Anyone know what I am doing wrong? I am supposed to make this console program as homework to learn about loops, but I am finding out more about other things. It is supposed to keep a running tab of salesperson's commission based a a 10% commission of each sale. Anyways, here is the code:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  
  namespace TubSales
  {
     class Program
     {
        static void Main(string[] args)
        {
           char initial;
           const double COMM_INT = 0.10;
           double sale, aComm = 0, bComm = 0, eComm = 0;
           Console.Write("Enter 'A' for Andrea, 'B' for Brittany,\n'E' for Eric, or 'Z' to quit &gt;&gt; ");
           initial = Convert.ToChar(Console.Read());
           while (initial != 'z' &amp;&amp; initial != 'Z')
           {
              switch (initial)
              {
                 case 'a':
                 case 'A':
                    Console.Write("Enter the sales for Andrea &gt;&gt; ");
                    sale = Convert.ToDouble(Console.ReadLine());
                    aComm = aComm + COMM_INT * sale;
                    break;
                 case 'b':
                 case 'B':
                    Console.Write("Enter the sales for Brittany &gt;&gt; ");
                    sale = Convert.ToDouble(Console.ReadLine());
                    bComm = bComm + COMM_INT * sale;
                    break;
                 case 'e':
                 case 'E':
                    Console.Write("Enter the sales for Eric &gt;&gt; ");
                    sale = Convert.ToDouble(Console.ReadLine());
                    eComm = eComm + COMM_INT * sale;
                    break;
                 default:
                    Console.WriteLine("You did not enter a valid initial");
                    break;
              }
              Console.Write("Enter 'A' for Andrea, 'B' for Brittany, or 'E' for Eric &gt;&gt; ");
              initial = (char)Console.Read();
           }
           Console.WriteLine("Andrea had {0}, Brittany had {1}, and Eric had {2} in commissions.", aComm.ToString("C"), bComm.ToString("C"), eComm.ToString("C"));
           Console.Write("Press any key to exit... ");
           Console.ReadKey();
        }
     }
  }
  </code></pre>