odoo/addons/point_of_sale/wizard/pos_return_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
	<data>        
		<record id="action_view_pos_return" model="ir.actions.act_window">
			<field name="name">Return lines</field>
			<field name="res_model">pos.return</field>
			<field name="view_type">form</field>
			<field name="view_mode">form</field>
			<field name="target">new</field>
		</record>	

        <record id="pos_return_tree_in" model="ir.ui.view">
            <field name="name">pos.return.memory</field>
            <field name="model">pos.return.memory</field>
            <field name="type">tree</field>
            <field name="arch" type="xml">
                <tree editable="bottom" string="Return Product">
                    <field name="product_id" />
                    <field name="quantity" />
                    <field name="line_id" invisible="1"/>
                </tree>
            </field>
        </record>
        
        <record id="pos_return_form_in" model="ir.ui.view">
            <field name="name">pos.return.memory</field>
            <field name="model">pos.return.memory</field>
            <field name="type">form</field>
            <field name="arch" type="xml">
                <form>
                    <field name="product_id" />
                    <field name="quantity" />
                    <field name="line_id" invisible="1"/>
                 </form>
            </field>
        </record>   
      
	</data>
</openerp>