Private Sub cmdConnect_Click()
On Error GoTo ErrorHandler

Set MyOPCServer = New OPCServer ' Create OPCServer Object

Call MyOPCServer.Connect(txtServer.Text) ' Disconnect from OPC Server

' Set Button Enable
cmdConnect.Enabled = False
cmdDisconnect.Enabled = True
cmdAddGroup.Enabled = True
Exit Sub
ErrorHandler:
MsgBox Err.Des cription + Chr(13) + "Connecting to OPC Server", vbCritical, "ERROR"
End Sub