Const ForReading = 1
Const ForAppending = 8
Dim ipLog, objHTTP, strHTML, varStart
Dim varStop, strIP, strCurrIP, objFSO
Dim txtFile, strLine, objShell

' Log for tracking external IP addresses
ipLog = "ExternalIP.txt"

' Get current external IP address from web
Set objHTTP = CreateObject("MSXML2.XMLHTTP")
Call objHTTP.Open("GET", "http://checkip.dyndns.org", False)
objHTTP.Send()
strHTML = objHTTP.ResponseText

' Extarct IP from HTML if HTML was recieved
If strHTML <> "" Then
	varStart = InStr(1, strHTML, "Current IP Address:", vbTextCompare) + 19
	If varStart Then varStop = InStr(varStart, strHTML, "</body>", vbTextCompare)
	If varStart And varStop Then strIP = Mid(strHTML, varStart, varStop - varStart)
Else
	strIP = "Unavailable"
End If
' Remove preceeding or trailing spaces
strCurrIP = Trim(strIP)

' Check for log file and last log entry
Set objFSO = CreateObject("Scripting.FileSystemObject")
If Not (objFSO.FileExists(ipLog)) Then
	' If log file doesn't exist create it
	Set txtFile = objFSO.CreateTextFile(ipLog, True)
	strIP = ""
Else
	' Get last external IP address entry from log file
	Set txtFile = objFSO.OpenTextFile(ipLog, ForReading)
	Do Until txtFile.AtEndOfStream
	   strLine = txtFile.ReadLine
	   If Len(strLine) > 0 Then
		  strIP = strLine
	   End If
	Loop

End If
txtFile.Close

' Extarct last external IP from log file entry
If strIP <> "" Then
	varStart = 1
	varStop = InStr(varStart, strIP, ",", vbTextCompare) - 1
	If varStop Then strIP = Mid(strIP, varStart, varStop - varStart)
	' Remove preceeding or trailing spaces
	Trim(strIP)
Else
	strIP = "Unavailable"
End If

' Copy IP to clipboard
Set objShell = WScript.CreateObject("WScript.Shell")
objShell.Run "CMD /C ECHO " & strCurrIP & " | CLIP", 2

' Check if external IP has changed
If strCurrIP = strIP Then
	' If unchanged display IP
	MsgBox "External IP:  " & strCurrIP & " is unchanged"
Else
	' If changed log to file and display IP
	Set txtFile = objFSO.OpenTextFile(ipLog, ForAppending)
	txtFile.Write(strCurrIP & vbTab & ", " & Date & vbCrLf)
	txtFile.Close
	MsgBox "External IP:  " & strCurrIP & vbCrLf & "This IP address has been logged"
End If

' Clear variables
Set ipLog = Nothing
Set objHTTP = Nothing
Set strHTML = Nothing
Set varStart = Nothing
Set varStop = Nothing
Set strIP = Nothing
Set strCurrIP = Nothing
Set objFSO = Nothing
Set txtFile = Nothing
Set strLine = Nothing
Set objShell = Nothing