'--- Toggles the state of the port (open or closed).
'
Sub MOpen_Click ()
    On Error Resume Next
    Dim OpenFlag

    MSComm1.PortOpen = Not MSComm1.PortOpen
    If Err Then MsgBox Error$, 48
    
    OpenFlag = MSComm1.PortOpen
    MOpen.Checked = OpenFlag
    MSendText.Enabled = OpenFlag
    MHangup.Enabled = OpenFlag
    
End Sub