xmlhttp POST isn't working - xmlhttprequest

Question

I'm trying to post transactions to server using a middleware client (it's called Cohesion). Below is my code (asp):
Dim xmlhttp 'As Object
Set xmlhttp = CreateObject("MSXML2.ServerXMLHTTP")
xmlhttp.Open "POST", "http://server_ip/Databox-dr/CohesionConnect.asmx/GetHostReply", False
'using only http://server_ip/Databox-dr/CohesionConnect.asmx doesn't work, either
xmlhttp.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"
'xmlhttp.setRequestHeader "Content-Length", "128"
xmlhttp.send "50000000000MSUF"
Set xmlhttp = Nothing
The documentation I have (and that's all of it) is tellin me this:
HTTP POST
The following is a sample HTTP POST request and response. The placeholders shown need to be replaced with actual values.
POST /DATABOX-DR/CohesionConnect.asmx/GetHostReply HTTP/1.1
Host: server_ip
Content-Type: application/x-www-form-urlencoded
Content-Length: length
sTran=string
HTTP/1.1 200 OK
Content-Type: text/xml; charset=utf-8
Content-Length: length
<?xml version="1.0" encoding="utf-8"?>
<string xmlns="http://fidelityifs.com/webservices">string</string>
(length and string need to replaced with real values)
What am I doing wrong? How can I set the string length?
Thanks!!

Answer 1

Try this:
Dim xmlhttp As Object
Set xmlhttp = CreateObject("MSXML2.ServerXMLHTTP")
xmlhttp.Open "POST", "http://server_ip/Databox-dr/CohesionConnect.asmx/GetHostReply", False
xmlhttp.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"
tosend = "50000000000MSUF"
s = "sTran=" & tosend
xmlhttp.setRequestHeader "Content-Length", Len(s)
xmlhttp.send s