Dear Sir, 
I wrote a program to retrieve price list everyday and the code I used is something like below:
            Dim URL as string = "https://technet.rapaport.com/HTTP/Prices/CSV2_Round.aspx"
            Dim webRequest As System.Net.WebRequest = System.Net.WebRequest.Create(URL)
            webRequest.Method = "POST"
            webRequest.ContentType = "application/x-www-form-urlencoded"
            Dim reqStream As Stream = webRequest.GetRequestStream()
            Dim postData As String = "username=xxx&password=xxx"
            Dim postArray As Byte() = Encoding.ASCII.GetBytes(postData)
            reqStream.Write(postArray, 0, postArray.Length)
            reqStream.Close()
I can get the most updated price list by using the above code. However, for some reason, I need to get back the price list of some days ago, e.g. price list of 2010/10/31. So is that a way to get  back the previous price list ?
Thanks