Sub InitializeForm()

Dim bitRates(9) As Integer
Dim nameArray() As String

' Find the COM ports on the system.

nameArray = SerialPort.GetPortNames
Array.Sort(nameArray)

' Fill a combo box with the port names.

cmbPorts.DataSource = nameArray
cmbPorts.DropDownStyle = _
ComboBoxStyle.DropDownList

' Select a default port.

cmbPorts.SelectedIndex = 1

'Bit rates to select from.

bitRates(0) = 300
bitRates(1) = 600
bitRates(2) = 1200
bitRates(3) = 2400
bitRates(4) = 9600
bitRates(5) = 14400
bitRates(6) = 19200
bitRates(7) = 38400
bitRates(8) = 57600
bitRates(9) = 115200

'Place the bit rates in a combo box.

cmbBitRate.DataSource = bitRates
cmbBitRate.DropDownStyle = _
ComboBoxStyle.DropDownList

' Select a default bit rate.

cmbBitRate.SelectedItem = 1200

End Sub

Listing 1. Combo boxes on the form enable users to select a port and bit rate.