Returned string from responseStream

Hi All, Thank U

here I am calling wsdl dynamically.I am not getting error here and the status code is 200. Now I want to know how can get the returned string from GetUsername in the  responseStream ??

ASMX code below

<%@ WebService Language="VB" Class="WebServiceDNNUser" %>

Imports System.Web
Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports DotNetNuke.Entities.Users

<WebService(Namespace:="http://www.xxx.com/")> _<WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
Public Class WebServiceDNNUser
    Inherits System.Web.Services.WebService
#Region "GetUsername()"<WebMethod> _
    Public Function GetUsername() As String
        Dim strUsername As String = ""
        ' Get the current user 
        Dim objUserInfo As UserInfo = UserController.GetCurrentUserInfo()

        ' If the user is not -1 they are logged in
        If objUserInfo.UserID > -1 Then
            strUsername = objUserInfo.Username
        End If
        Return strUsername
    End Function
#End Region


End Class

code behind

 Dim soap As String = "<?xml version=""1.0"" encoding=""utf-8""?><soap:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/""><soap:Body>  <GetUsername xmlns=""http://www.xxx.om/"" />  </soap:Body></soap:Envelope>"
        Dim req As HttpWebRequest = DirectCast(WebRequest.Create("http://xxx.om/WebServiceDNNUser.asmx"), HttpWebRequest)
        req.Headers.Add("SOAPActionhttp://www.xxx.om/GetUsername")
        req.ContentType = "text/xml;charset=""utf-8"""
        req.Accept = "text/xml"
        req.Method = "POST"
        Using stm As Stream = req.GetRequestStream()
            Using stmw As New StreamWriter(stm)
                stmw.Write(soap)
            End Using
        End Using
        Dim response As WebResponse = req.GetResponse()
        Dim responseStream As Stream = response.GetResponseStream()