Do you mean upload a file?
the following form will do that
<FORM ENCTYPE=\"multipart/form-data\" ACTION=\"_URL_\" METHOD=\"POST\">
<INPUT TYPE=\"hidden\" name=\"MAX_FILE_SIZE\" value=\"1000\">
Send this file: <INPUT NAME=\"file\" TYPE=\"file\">
<INPUT TYPE=\"submit\" VALUE=\"Send File\">
</form>
You can also put it in a mail form.
Ian