odoo/addons/point_of_sale/wizard/pos_receipt_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data>

    <!--   pos.details -->

    <record id="view_pos_receipt" model="ir.ui.view">
      <field name="name">Receipt</field>
      <field name="model">pos.receipt</field>
      <field name="type">form</field>
      <field name="arch" type="xml">
        <form string="Receipt :">
          <button icon='gtk-cancel' special="cancel"
                  string="Close" />
          <button name="print_report" string="Print Report"
                  colspan="1" type="object" icon="gtk-ok" />
        </form>
      </field>
    </record>

    <act_window name="Print Receipt"
        res_model="pos.receipt"
        src_model="pos.order"
        view_mode="form"
        target="new"
        key2="client_action_multi"
        id="action_report_pos_receipt"/>

      <!--record id="action_report_pos_receipt" model="ir.actions.act_window">
            <field name="name">Receipt</field>
            <field name="res_model">pos.receipt</field>
            <field name="view_type">form</field>
            <field name="view_mode">form</field>
             <field name="target">new</field>
        </record-->

</data>
</openerp>