... After the request has been submitted

[PROKA]

I make a request , then I use it , then I make another request using the same variable .
I get the error message :

This operation cannot be performed after the request has been submitted

    Dim link As String = "http://www.mysite.com"
    Dim toxigen As WebRequest = WebRequest.Create(link)
    Dim myProxy As New WebProxy
    Dim proxyAddress As String
    Dim newUri As Uri
    Dim myWebResponse As WebResponse

In some sub I have ...

newUri = New Uri(proxyAddress)

            myProxy.Address = newUri
            toxigen.Proxy = myProxy


            myWebResponse = toxigen.GetResponse()

Then when I call again the sub, I get the error .
Well I tried to myWebResponse.close() but I still get the error