[web2py] update db.table from custom form

[cyber]

Hi there! Say guys how can I handle form.accepts if I need update
record in db from my custom form?

I have the custom form in one view:
{{from r in current_row:}}
<form>
   ...
   <input type="button" value={{=r.enter}} />
   ...
</form>
{{pass}}

And I want to update db.table.enter from "False" to "True" when user
presses the button. How can I do that?