VB.net sample code to add/update a subscriber

Public Function AddSubscriber() As String

        Dim data As New StringBuilder()
        Dim ll_ret As String = ""
        Dim l_username As String = "USERNAME"
        Dim l_password As String = "PASSWORD"
        Dim l_listid As String = "LISTID"
        Dim l_email As String = "test@criticalimpact.com"
        Dim l_firstname As String = "Testfirst"
        Dim l_lastname As String = "Testlast"

        Try

            Dim l_posturl = "http://clients.criticalimpact.com/api/api.cfm"
            data.Append("c=")
            data.Append("<?xml version=""1.0""?>")
            data.Append("<criticalimpact>")
            data.Append("<login>")
            data.Append("   <username>" & l_username & "</username>")
            data.Append("   <password>" & l_password & "</password>")
            data.Append("</login>")
            data.Append("  <command>")
            data.Append("    <action>subscriberadd</action>")
            data.Append("    <listid>" & l_listid & "</listid>")
            data.Append("    <email><![CDATA[" & l_email & "]]></email>")
            data.Append("    <firstname><![CDATA[" & l_firstname & "]]></firstname>")
            data.Append("    <lastname><![CDATA[" & l_lastname & "]]></lastname>")
            data.Append("    <unsubscribe>0</unsubscribe>")
            data.Append("    <listunsubscribe>0</listunsubscribe>")
            data.Append("    <custom1>Sample Value</custom1>")
            data.Append("    <custom2>Sample Value</custom2>")
            data.Append("    <custom3>Sample Value</custom3>")
            data.Append("    <custom4>Sample Value</custom4>")
            data.Append("  </command>")
            data.Append("</criticalimpact>")

            'NEW METHOD SO WE CAN SET A TIMEOUT
            ' Create a request using a URL that can receive a post. 
            Dim request As WebRequest = WebRequest.Create(l_posturl)
            Dim l_response As String = ""

            ' Set the Method property of the request to POST.
            request.Method = "POST"

            ' Create POST data and convert it to a byte array.
            Dim byteArray As Byte() = Encoding.UTF8.GetBytes(data.ToString)

            ' Set the ContentType property of the WebRequest.
            request.ContentType = "application/x-www-form-urlencoded"

            ' Set the ContentLength property of the WebRequest.
            request.ContentLength = byteArray.Length

            ' Get the request stream.
            Dim dataStream As Stream = request.GetRequestStream()

            ' Write the data to the request stream.
            dataStream.Write(byteArray, 0, byteArray.Length)

            ' Close the Stream object.
            dataStream.Close()

            ' Get the response.
            Dim response As WebResponse = request.GetResponse()

            ' Display the status.
            l_response = l_response & "StatusDescription:" & (CType(response, HttpWebResponse).StatusDescription) & vbCrLf

            ' Get the stream containing content returned by the server.
            dataStream = response.GetResponseStream()

            ' Open the stream using a StreamReader for easy access.
            Dim reader As New StreamReader(dataStream)

            ' Read the content.
            Dim responseFromServer As String = reader.ReadToEnd()

            ' Display the content.
            l_response = l_response & "ServerResponse:" & responseFromServer & vbCrLf
            ll_ret = responseFromServer.Trim()

            ' Clean up the streams.
            reader.Close()
            dataStream.Close()
            response.Close()


        Catch ex As System.Net.WebException
            'Error in accessing the resource, handle it
            MsgBox("Error: " & Err.Description)
        End Try

        Return ll_ret

    End Function