account-reconcile/account_statement_cancel_line/statement_view.xml

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

        <record id="view_bank_statement_form_cancel_line" model="ir.ui.view">
            <field name="name">account.bank.statement.form.</field>
            <field name="inherit_id" ref="account.view_bank_statement_form" />
            <field name="model">account.bank.statement</field>
            <field name="arch" type="xml">
                <data>
                    <xpath expr="//field[@name='line_ids']/tree/field[@name='amount']"
                           position="after">
                        <field name="state"/>
                        <button name="confirm" states="draft"
                                string="Confirm transaction"
                                icon="gtk-ok"
                                type="object"/>
                        <button name="button_cancel" states="confirmed"
                                string="Cancel transaction"
                                icon="gtk-cancel"
                                type="object"/>
                    </xpath>
                </data>
            </field>
        </record>

    </data>
</openerp>