[web2py] crud.create -> crud.read and crud.update if necessary

[Jean-Guy]

Hello,

I am trying to figure it out how I may add a button on crud.read form 
that redirect if pressed on crud.update form.

I would like my users to be able to modify their seizures mistakes if 
they made some...

To not make update to the database if the data are correct I redirect 
them to crud.read form before let them confirm or update their data with 
crud.update.

Here my controller :

def test():
    if auth.has_membership(auth.id_group('gr1')):
        form = SQLFORM(db.atable)
    elif auth.has_membership(auth.id_group('gr2')):
        form = SQLFORM(db.atable,deletable=True)
    elif auth.has_membership(auth.id_group('gr3')):
        form = crud.create(db.atable)
    if form.accepts(request.vars, session):
        response.flash = T('form accepted')
        form=crud.read(db.atable,form.vars.id) # I don't know how to 
create a "update button"
        if form: # here I don't know how to verify if the "update 
button" is _onclick
            form=crud.update(db.atable,form.vars.id)
    elif form.errors:
        response.flash = T('form has errors')
    else:
        response.flash = T('please fill out the form')
    return dict(form=form)

Thanks

Jonhy