Visual Basic 6.0

To make a simple temperature conversion program, create a project with the following objects:
frmMain Caption = "°F/°C Converter" txtData Text = "" optF Caption = "°F" optC Caption = "°C" lblEq Caption = "=" lblAnswer Caption = "Answer" lblUnit Caption = "°"

Then Copy/Paste this code:
Private Sub optF_Click() Call Convert End Sub Private Sub optC_Click() Call Convert End Sub Private Sub txtData_KeyUp(KeyCode As Integer, Shift As Integer) Call Convert End Sub Private Sub Convert() Dim TempF, TempT If optF.Value = True Then If IsNumeric(txtData.Text) Then TempF = txtData.Text Else: TempF = 0 End If TempT = (TempF - 32) * 5 / 9 lblAnswer.Caption = TempT lblUnit.Caption = "°C" End If If optC.Value = True Then If IsNumeric(txtData.Text) Then TempF = txtData.Text Else: TempF = 0 End If TempT = (TempF * 9 / 5) + 32 lblAnswer.Caption = TempT lblUnit.Caption = "°F" End If End Sub

eMbedded Visual Basic 3.0

Make the same form and Copy/Paste the same code as above, but replace the Private Sub txtData_KeyUp event line with this one:
Private Sub txtData_KeyUp(ByVal KeyCode As Integer, ByVal Shift As Integer)

What's Happening?

The optF_Click event (when the °F option is selected), the optC_Click event (when the °C option is selected), and the txtData_KeyUp event (when focus is on the text box and a key is pressed and released on the keyboard) trigger the Convert() code. The code checks if the conversion is °F to °C or °C to °F based on the option selection. The code also makes sure the data in the text box is a number (otherwise letters, a negative sign, or an empty text box from using back space would cause an error) - if it is not a number, it uses a zero value. Then the code converts the data, changes the lblAnswer caption to the answer, and changes the lblUnit caption to the appropriate unit (oppossite of selection).

Just a note - you can type the "°" character by holding down Alt key and typing "248" on the Num Pad, and then releasing the Alt key (you can also use "0176").