<form model="clinic.period">
    <head>
        <button string="Options" dropdown="1">
            <item string="Generate Period" method="gen_period"/>
        </button>
    </head>
    <group form_layout="stacked">
        <field name="name" span="2"/>
        <field name="date_start" span="2"/>
        <field name="date_stop" span="2"/>
        <field name="nmonth" span="2"/>
        <field name="last_period_id" span="3"/>
        <field name="lines" nolabel="1">
            <list>
                <field name="date_start"/>
                <field name="date_stop"/>
                <field name="day_total"/>
                <field name="state"/>
            </list>
        </field>
    </group>
    <foot>
        <button string="Close Period" type="danger" method="close_period"/>
    </foot>
</form>