Communicating between PC and Arduino (Correction)

On March 19th, 2012, a youtube user called Sophie333C found a problem on video "Communicating between PC and Arduino".

Sophie333C's comment:
Hi, There seems to be a problem when you press send the second time around,
it only seems to update every second press of the button!

After two days, she sent me a solution. I tested her solution and it works fine. Now I can receive a answer
when I press the button for first time. Here is code of solution:

  answer = port_arduino.ReadByte()
        TextBox2.Text = Chr(answer)

I would like thank to Sophie333C to found out this problem.