<%@Import Namespace="System.Drawing.Imaging" %>

<script language="VB" runat="server">

  Sub Page_Load(sender as Object, e as EventArgs)

  

    'Read in the image filename to create a thumbnail of

    Dim imageUrl as String = Request.QueryString("img")

    

    'Make sure that the image URL doesn't contain any /'s or \'s

    If imageUrl.IndexOf("/") >= 0 Or imageUrl.IndexOf("\") >= 0 then

      'We found a / or \

      Response.End()

    End If

    

    'Add on the appropriate directory

    imageUrl = "/images/" & imageUrl

    

    'Get the image.    

    Dim fullSizeImg as System.Drawing.Image

    fullSizeImg = System.Drawing.Image.FromFile(Server.MapPath(imageUrl))

    

    'Set the ContentType to "image/gif" and output the image's data

    Response.ContentType = "image/gif"

    fullSizeImg.Save(Response.OutputStream, ImageFormat.Gif)  

  End Sub

</script>