[mod_python] redirect with location header

I want to do something like this:

- user go to url something/edit 
- ..fills form and submits it to the same url (something/edit)

then i catch this submitted form, validate it and if it passess
validation i want to do redirection to something/index (so
that user which submitted form, edited something is redirected
back to index page). but if the form is wrong i want user to stay
at edition page and refill this form - there is no redirection.

i have a problem with the first case. when user submits a form,
i go to url /add, do what i want to do and then i send a location
header which redirects me to /index. but when i do this, browser
asks me whether i want to repost my submitted form to this
new url (/index). is there any way to redirect totally 
transparently for user, so that browser won't ask this question?

/K