How to add a button in the seletions "More"

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="view_sale_order_make_invoice" model="ir.ui.view">
            <field name="name">Create invoices</field>
            <field name="model">sale.make.invoice</field>
            <field name="arch" type="xml">
                <form string="Create invoices" version="7.0">
                    <separator colspan="4" string="Do you really want to create the invoice(s)?" />
                    <group>
                        <field name="grouped"/>
                        <field name="invoice_date"/>
                    </group>
                    <footer>
                        <button name="make_invoices" string="Create Invoices" type="object" class="oe_highlight"/>
                        or
                        <button string="Cancel" class="oe_link" special="cancel" />
                    </footer>
               </form>
            </field>
        </record>

        <record id="action_sale_order_make_invoice" model="ir.actions.act_window">
            <field name="name">Make Invoices</field>
            <field name="type">ir.actions.act_window</field>
            <field name="res_model">sale.make.invoice</field>
            <field name="view_type">form</field>
            <field name="view_mode">form</field>
            <field name="view_id" ref="view_sale_order_make_invoice"/>
            <field name="target">new</field>
            <field name="multi">True</field>
        </record>

        <record model="ir.values" id="sale_order_make_invoice">
            <field name="model_id" ref="sale.model_sale_order" />
            <field name="name">Make Invoices</field>
            <field name="key2">client_action_multi</field>
            <field name="value" eval="'ir.actions.act_window,' + str(ref('action_sale_order_make_invoice'))" />
            <field name="key">action</field>
            <field name="model">sale.order</field>
        </record>
    </data>
</openerp>

Key points:

<field name="multi">True</field>

and

<record model="ir.values" id="sale_order_make_invoice">
            <field name="model_id" ref="sale.model_sale_order" />
            <field name="name">Make Invoices</field>
            <field name="key2">client_action_multi</field>
            <field name="value" eval="'ir.actions.act_window,' + str(ref('action_sale_order_make_invoice'))" />
            <field name="key">action</field>
            <field name="model">sale.order</field>
        </record>



myselft Note:
in wizard xml file write:    <field name="multi">True</field>
second:

<record model="ir.values" id="pcb_several_make_pcb_severalone">
            <field name="model_id" ref="pcb_several.model_pcb_several" />
            <field name="name">PCB Several One</field>
            <field name="key2">client_action_multi</field>
            <field name="value" eval="'ir.actions.act_window,' + str(ref('action_password_several'))" />
            <field name="key">action</field>
            <field name="model">pcb.several</field>
        </record>