I've created a wizard for alert on a condition and that does a good job to me. For people with similar prob i am placing my idea below

My New Wizard class

class sale_order_confirm(osv.osv):
    _name = "sale.order.confirm"
    _description = "Sales Order Confirm"
    def action_confirm(self, cr, uid, ids, context=None):
        assert len(ids) == 1, 'This option should only be used for a single id at a time.'
        wf_service = netsvc.LocalService('workflow')
        wf_service.trg_validate(uid, 'sale.order', ids[0], 'order_confirm', cr)

        # redisplay the record as a sales order
        view_ref = self.pool.get('ir.model.data').get_object_reference(cr, uid, 'sale', 'view_order_form')
        view_id = view_ref and view_ref[1] or False,
        return {
            'type': 'ir.actions.act_window',
            'name': _('Sales Order'),
            'res_model': 'sale.order',
            'res_id': ids[0],
            'view_type': 'form',
            'view_mode': 'form',
            'view_id': view_id,
            'target': 'current',
            'nodestroy': True,
        }
sale_order_confirm()

My view record

<record id="view_cancel_order" model="ir.ui.view">
            <field name="name">Cancel Repair</field>
            <field name="model">sale.order.confirm</field>
            <field name="arch" type="xml">
                <form string="Confirm Sale Order" version="7.0">
                    <group>
                        <label string="This Sale Order will be confirmed with service Product. Agree?"/>
                    </group>
                    <footer>
                        <button name="action_confirm" string="Yes" type="object" class="oe_highlight"/>
                        or
                        <button string="Cancel" class="oe_link" special="cancel" />
                    </footer>
                </form>
            </field>
        </record>

I've changed my action_button_confirm function in the sale_order.py slightly

def action_button_confirm(self, cr, uid, ids, context=None):
        assert len(ids) == 1, 'This option should only be used for a single id at a time.'
        is_optional_item_exists = False    # here i can check for wt ever condition and this variable will have the resul
        so_obj = self.browse(cr, uid, ids, context)
        if so_obj:
            for line in so_obj[0].order_line:
                print line.name
                if line.is_optional_item:
                     is_optional_item_exists = True

        if(is_optional_item_exists):
            return {
                'name': 'Order Confirmation',
                'view_type': 'form',
                'view_mode': 'form',
                'res_model': 'sale.order.confirm',
                'type': 'ir.actions.act_window',
                'nodestroy': True,
                'target': 'new',
                }
        else:
            wf_service = netsvc.LocalService('workflow')
            wf_service.trg_validate(uid, 'sale.order', ids[0], 'order_confirm', cr)

            # redisplay the record as a sales order
            view_ref = self.pool.get('ir.model.data').get_object_reference(cr, uid, 'sale', 'view_order_form')
            view_id = view_ref and view_ref[1] or False,
            return {
                'type': 'ir.actions.act_window',
                'name': _('Sales Order'),
                'res_model': 'sale.order',
                'res_id': ids[0],
                'view_type': 'form',
                'view_mode': 'form',
                'view_id': view_id,
                'target': 'current',
                'nodestroy': True,
            }

Thanks All and Cheers!!