file upload validation

I am checking the MIME types for upload file that I only accept for and they are working accept for ppt file. I don't see the ppt file available from <input type="file" accept="" either. Is any has any experience on this?

<cfset request.AcceptImage= "image/gif,image/jpg,image/jpeg,image/pjpeg,image/x-png,application/pdf,application/ppt">

<cffile action="Upload" filefield="file_only" destination="#products_files#\" nameconflict="OVERWRITE" accept="#request.AcceptImage#">

Thanks