How to download a text file while I am using Asp.net 2.0 and Ajax ?

[Payodhi]

Dim fs As System.IO.FileStream = Nothing
fs = File.Open(Server.MapPath("TextFiles/Agent/" + filenam + ".txt"), System.IO.FileMode.Open)
Dim btFile(fs.Length) As Byte
fs.Read(btFile, 0, fs.Length)
fs.Close()
Context.ClearError()
With Response
.AddHeader("Content-disposition", "attachment;filename=" & filenam)
.ContentType = "application/octet-stream"
.BinaryWrite(btFile)
.End()
End With

See, this code block was runing absolutely fine before using Ajax.Ajax does not support Respone.Write.So what will be the solution ?Awaiting for your reply.
Please......Please...... Please