Help with MSXML and Visual Studio 2013

Hi
I am having problems trying to use MSXML in Visual Studio 2013.
My old code worked fine in Visual Studio 2003:

Imports System.Data
Imports System.Data.Odbc
Imports System.IO
Imports System.Net.HttpWebRequest
Imports System.Net.WebRequest
Imports System.Net.WebResponse
Imports System.Xml.XmlDocument
Imports MSXML
.......
Public function ProvisionService as boolean
            Dim XMLReq As New MSXML.XMLHTTPRequest
            Dim xmlHttp As New XMLHTTPRequest
            Dim r As System.Object
            Dim xmlDoc As String
            Dim xmlr As XMLDocument
            Dim URL As String
            Dim Asynch As Boolean

However in VS2013, it doesn't recognise the MSXML.XMLHTTPRequest or XMLDocument types.  I am getting the compile error: "Error      5      Type 'XMLHTTPRequest' is not defined".

Can anyone help me get this sorted?  I am sure there must be a simple solution but I am stumped!

thanks