Visual Basic

If port.bytesToRead > 0 then
checkforillegalcrossthreadcalls = false      <<<<<<< never do this, it is BAD
Dimbytetoread as integer

bytetoread = port.bytestoread
Dim array as byte() = new byte(bytetoread - 1)()
Dim linedata as string
port.read(bytearray, 0, bytetoread)           <<<<<<< bytearray or array???
linedata = converttostring(bytearray)         <<<<<<< use Encoding.ASCII.GetString


txtcommand.text = linedata                    <<<<<<< use txtcommand.InvokeRequired pattern
port.close()

Public Class SomeClass
 
    Public Event WorkCompleted(ByVal e As WorkCompletedEventArgs)
 
    ...
        RaiseEvent WorkCompleted(New WorkCompletedEventArgs(someValue, someOtherValue))
    ...
End Class
 
Public Class WorkCompletedEventArgs
    ' Expose Public properties that will
    ' return values to the subscriber.
    ' You might want to include a New (constructor)
    ' that set's these values instead of just
    ' relying on an empty constructor.

    Public Sub New(ByVal value1 As Integer, ByVal value2 As String)
        Me.myValue = value1
        Me.myString = value2
    End Sub
End Class

Dim num10 As Integer  ' Number of $10 bills
  Dim Num20 As Integer   ' Number of $20 bills
  Dim dAmt As Double   ' Amount of money to be converted

  dAmt = 50.35

  Num20 = Int(dAmt) / 20

  dAmt = dAmt - (Num20 * 20)

  Num10 = Int(dAmt) / 10

  MsgBox("Number of $20: " + CStr(Num20) + "  Number of $10: " + CStr(num10))