Dundas Upload is a server-side component that can be used to upload files from a client's machine to the server, under your domain.

How do you use Dundas Upload?
The following is an example of using the Upload component to upload a file:

    <%
        'Create an instance of our Upload object.
        Set uploadObj = Server.CreateObject("Dundas.Upload.2")

        'Disable unique names, to preserve the original filename.
        uploadObj.UseUniqueNames = False

        'We need to catch any errors
        On Error Resume Next
        uploadObj.Save Server.MapPath(".")
        If (Err <> 0) Then
            Response.Write "An error occured: " & Err.Description
        End If
    %>

The standard Request.Form collection becomes unusable when the Dundas.Upload.2 object is instantiated, to access the values of the Form collection, use something similar to this:

    <%
        formValue = uploadObj.Form("formField")
        'Where formField is a field input that was posted.
    %>

Posting a Form
When you post a form to your script, if it contains a file field (<input type="file" />), you need to specify an encoding type.  This can be done as follows:

    <form action="..." method="post" enctype="multipart/form-data">

Permissions
The permissions on your hosting account are setup to allow scripts to operate in a secure manner.  Uploading files will work when the Save path is one that is under your domain.  Trying to save to files outside of your domain will result in an access violation and your script will finish in error.