'Assign the set of allowable next actions.
Arguments:
values -- A list containing any combination of:
\'prev\', \'next\', and \'complete\''

def set_actions(self, values):

    self.del_actions()
    if values:
        self._set_sub_text(('{%s}actions' % self.namespace), '', True)
        actions = self.find(('{%s}actions' % self.namespace))
        for val in values:
            if (val in self.next_actions):
                action = ET.Element(('{%s}%s' % (self.namespace, val)))
                actions.append(action)
