msxml.serverxmlhttp not submitting form data

I'm attempting to use the msxml.serverxmlhttp component to submit form data from one server to another using the method outlined below.  The only problem is that the receiving asp doesn't see the form data.  It behaves as if i've submitted an empty form; no errors, just no data.

Does anyone know why this is happening?

Thanks

<%@ Language=vbScript%>
<%
     DataToSend = "id=1"
     dim xmlhttp
     set xmlhttp = server.Createobject("MSXML2.ServerXMLHTTP")
     xmlhttp.Open "POST","http://localhost/Receiver.asp",false
     xmlhttp.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"
     xmlhttp.send DataToSend
     Response.ContentType = "text/xml"
     Response.Write xmlhttp.responsexml.xml
        Set xmlhttp = nothing

%>