How To Change File Name On Front End Automatically In An ASP Upload

I am working with a client now who wants to upload files to his web server using ASP/VBScript.  I found a nice little script to do it quick and dirty at

http://www.freeaspupload.net/

However, client is now (justifiably) worried about duplicate file names; this script doesn't handle them--it simply overwrites the old file.

Is there a way I can customize file names on the front end so as to avoid duplicate file names?  I want to avoid installing components on the web server b/c the server admin is uncomfortable doing it, and it's potentially costly, etc.  Plus, we just had a whole lot of trouble with permisions to get dynamic DB app working, so I hate to make another server request unless I absolutely have to!

I am pretty good with Javascript, but not so great with ASP/VBScript (I let DW 8 do that for me).  I tried creating a new Recordset on the page and customizing the form field value with a dynamically generated unique field in the DB (such as ID or firstname = lastname), but I kept making the VBScript angry and crashing the whole app! (Variety of errors--but mainly "Must use only one instance of % on ASP page"--pretty obvious to me what it means but not savvy enough with VBScript to fix!)

Any help would be appreciated.  I have a feeling this might be solvbed with something fairly simple, but I am too "in the middle of things" right now to see clearly!

Here is the code I took from freeaspload.net, with just a few lines tailored for my purposes.  The code is one page that serves as both the form and the processor of form.  It is published on a web server running IIS.

<%@ Language=VBScript %>
<%
option explicit
Response.Expires = -1
Server.ScriptTimeout = 600
%>
<!-- #include file="freeASPUpload.asp" -->
<%


' ****************************************************
' Change the value of the variable below to the pathname
' of a directory with write permissions, for example "C:\Inetpub\wwwroot"
  Dim uploadsDirVar
  uploadsDirVar = "C:\Inetpub\wwwroot\wn\db"
' ****************************************************

' Note: this file uploadTester.asp is just an example to demonstrate
' the capabilities of the freeASPUpload.asp class. There are no plans
' to add any new features to uploadTester.asp itself. Feel free to add
' your own code. If you are building a content management system, you
' may also want to consider this script: http://www.webfilebrowser.com/

function OutputForm()
%>
    <form name="frmSend" method="POST" enctype="multipart/form-data" action="uploadTester.asp" onSubmit="return onSubmitForm();">
      <B>File names:</B><br>
    File 1: <input name="attach1" type="file" size=35><br>
    <br>
      <!-- These input elements are obviously optional and just included here for demonstration purposes -->
      <B>Additional fields (demo):</B><br>
      Enter a number: <input type="text" name="enter_a_number"><br>
    Checkbox values: <input type="checkbox" value="1" name="checkbox_values">-1 <input type="checkbox" value="2" name="checkbox_values">-2<br>
      <!-- End of additional elements -->
    <input style="margin-top:4" type=submit value="Upload">
    </form>
<%
end function

function TestEnvironment()
    Dim fso, fileName, testFile, streamTest
    TestEnvironment = ""
    Set fso = Server.CreateObject("Scripting.FileSystemObject")
    if not fso.FolderExists(uploadsDirVar) then
        TestEnvironment = "<B>Folder " & uploadsDirVar & " does not exist.</B><br>The value of your uploadsDirVar is incorrect. Open uploadTester.asp in an editor and change the value of uploadsDirVar to the pathname of a directory with write permissions."
        exit function
    end if
    fileName = uploadsDirVar & "\test.txt"
    on error resume next
    Set testFile = fso.CreateTextFile(fileName, true)
    If Err.Number<>0 then
        TestEnvironment = "<B>Folder " & uploadsDirVar & " does not have write permissions.</B><br>The value of your uploadsDirVar is incorrect. Open uploadTester.asp in an editor and change the value of uploadsDirVar to the pathname of a directory with write permissions."
        exit function
    end if
    Err.Clear
    testFile.Close
    fso.DeleteFile(fileName)
    If Err.Number<>0 then
        TestEnvironment = "<B>Folder " & uploadsDirVar & " does not have delete permissions</B>, although it does have write permissions.<br>Change the permissions for IUSR_<I>computername</I> on this folder."
        exit function
    end if
    Err.Clear
    Set streamTest = Server.CreateObject("ADODB.Stream")
    If Err.Number<>0 then
        TestEnvironment = "<B>The ADODB object <I>Stream</I> is not available in your server.</B><br>Check the Requirements page for information about upgrading your ADODB libraries."
        exit function
    end if
    Set streamTest = Nothing
end function

function SaveFiles
    Dim Upload, fileName, fileSize, ks, i, fileKey

    Set Upload = New FreeASPUpload
    Upload.Save(uploadsDirVar)

      ' If something fails inside the script, but the exception is handled
      If Err.Number<>0 then Exit function

    SaveFiles = ""
    ks = Upload.UploadedFiles.keys
    if (UBound(ks) <> -1) then
        SaveFiles = "<B>Files uploaded:</B> "
        for each fileKey in Upload.UploadedFiles.keys
            SaveFiles = SaveFiles & Upload.UploadedFiles(fileKey).FileName & " (" & Upload.UploadedFiles(fileKey).Length & "B) "
        next
    else
        SaveFiles = "The file name specified in the upload form does not correspond to a valid file in the system."
    end if
      SaveFiles = SaveFiles & "<br>Enter a number = " & Upload.Form("enter_a_number") & "<br>"
      SaveFiles = SaveFiles & "Checkbox values = " & Upload.Form("checkbox_values") & "<br>"
end function
%>

<HTML>
<HEAD>
<TITLE>Test Free ASP Upload</TITLE>
<style>
BODY {background-color: white;font-family:arial; font-size:12}
</style>
<script>
function onSubmitForm() {
    var formDOMObj = document.frmSend;
    if (formDOMObj.attach1.value == "" && formDOMObj.attach2.value == "" && formDOMObj.attach3.value == "" && formDOMObj.attach4.value == "" )
        alert("Please press the browse button and pick a file.")
    else
        return true;
    return false;
}
</script>

</HEAD>

<BODY>

<br><br>
<div style="border-bottom: #A91905 2px solid;font-size:16">Upload files to your server</div>
<%
Dim diagnostics
if Request.ServerVariables("REQUEST_METHOD") <> "POST" then
    diagnostics = TestEnvironment()
    if diagnostics<>"" then
        response.write "<div style=""margin-left:20; margin-top:30; margin-right:30; margin-bottom:30;"">"
        response.write diagnostics
        response.write "<p>After you correct this problem, reload the page."
        response.write "</div>"
    else
        response.write "<div style=""margin-left:150"">"
        OutputForm()
        response.write "</div>"
    end if
else
    response.write "<div style=""margin-left:150"">"
    OutputForm()
    response.write SaveFiles()
    response.write "<br><br></div>"
end if

%>



</BODY>
</HTML>