sub or function?

[Iain17]

Private Sub fillTextBox (strText as String, txtBox as TextBox)
 
    'clear all of the text boxes
    txtMain.Text = ""
    txtOne.Text = "" 
    txtTwo.Text = "" 
    txtThree.Text = "" 
    txtFour.Text = "" 

    if strText = "" then
      txtBox.Text = strMain
    else
      strMain = strText      
      txtBox.Text = strText
    End if

End Sub

private sub command1_click()

    'pass the data in the txtMain, and the textBox to be changed
    filltextBox txtMain.Text, txtOne

End Sub

private sub command2_click()

    filltextBox txtMain.Text, txtTwo

End Sub