Send excel file to user in web

Private Sub ExportFile(ByVal strfilePath As String, ByVal strFilename As String)
Try
Response.Clear()
Response.ContentType = "application/vnd.ms-excel"
strfilePath = Server.MapPath(strfilePath)
If Not System.IO.File.Exists(strfilePath) Then
strfilePath = Server.MapPath("~//Data//ExportToExcel//NoRecord.xls")
Response.AddHeader("content-disposition", ("attachment;filename=" + ("NoRecord" + ".xls")))
Else
Response.AddHeader("content-disposition", ("attachment;filename=" _
+ (strFilename + ".xls")))
End If

        Dim sourcefile As FileStream = New FileStream(strfilePath, FileMode.Open)
        Dim filesize As Long
        filesize = sourcefile.Length
        Dim getcontent() As Byte = New Byte((CType(filesize, Integer)) - 1) {}
        sourcefile.Read(getcontent, 0, CType(sourcefile.Length, Integer))
        sourcefile.Close()
        Response.BinaryWrite(getcontent)
    Catch ex As Exception
        ex = ex
    Finally
        Response.End()
    End Try

End Sub