Hi Shaffaf,

You simply make a button in the XML with a function defined in it like this:

<button name="your_button" string="Send e-mail" type="object" class="btn-primary"/>

Then define a Python function where you set the boolean to true:

@api.multi
def your_button(self):
    self.your_boolean_field = True

Regards,
Yenthe

How would the syntax be if my checkbox is in the model of sale.order and my button in account.move?