Is it possible to use 2 "file_field" in the same form?

I have one working perfectly, but when i add a second, like:

<%= start_form_tag ({:action => ‘create’}, :multipart => true) %>

<%= file_field “product”, “picture” %>
<%= file_field “product”, “thing” %

<%= submit_tag “Create” %>
<%= end_form_tag %>

Safari gives me a posix error:

further to this, it appears to work fine in firefox.
anyone have any idea why safari doesnt like it?

found the solution:
http://docs.info.apple.com/article.html?artnum=302946