Reset and Retain data in Text Fields on RoR Forms

1) don't use start_form_tag and end_form_tag -> they've been
deprecated. Use form_tag or form_for instead.

2) when/how do you want to reset the text field? Do you want to have a
button that the user can press to reset the text field? If so, you
can use javascript to do this..

3) what do you mean "retain the values"? Retain them where? Store them
to a database? Keep the values in the text fields if the user submits
a form with errors? Please elaborate.