Open the Upload.aspx page for the Document Library of the Site in
FrontPage 2003 and find the following tag in the code  window:

<WebPartPages:WebPartZone runat="server" FrameType="None" ID="Main"
Title="loc:Main">

Paste the following code just after the WebPartZone tag:

<WebPartPages:ContentEditorWebPart runat="server" WebPart="true"
__WebPartId="{DEDFBEB7-F0C8-4287-A36A-B2D2237CE7CE}" >
<WebPart xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://schemas.microsoft.com/WebPart/v2">
<Title>Content Editor Web Part</Title>
<FrameType>Default</FrameType>
<Description>Use for formatted text, tables, and images.</Description>
<IsIncluded>true</IsIncluded>
<PartOrder>1</PartOrder>
<FrameState>Normal</FrameState>
<Height />
<Width />
<AllowRemove>true</AllowRemove>
<AllowZoneChange>true</AllowZoneChange>
<AllowMinimize>true</AllowMinimize>
<IsVisible>true</IsVisible>
<DetailLink />
<HelpLink />
<Dir>Default</Dir>
<PartImageSmall />
<MissingAssembly />
<PartImageLarge>/_layouts/images/mscontl.gif</PartImageLarge>
<IsIncludedFilter />
<ExportControlledProperties>false</ExportControlledProperties>
<ConnectionID>00000000-0000-0000-0000-000000000000</ConnectionID>
<ContentLink
xmlns="http://schemas.microsoft.com/WebPart/v2/ContentEditor" />
<Content
xmlns="http://schemas.microsoft.com/WebPart/v2/ContentEditor"><![CDATA[<
script language="javascript">
function MultipleUploadView()
{
alert('Multiple Document upload  is not enabled');
}
</script>]]></Content>
<PartStorage
xmlns="http://schemas.microsoft.com/WebPart/v2/ContentEditor" />
</WebPart>
</WebPartPages:ContentEditorWebPart>


The user will not get a JavaScript alert rather than being taken to the
multiple file upload page.

If you understand how to use the Ghost Hunter Web Part, you will want to
reghost the page.