Inherit a predefined view.

I am new to OpenERP and trying to understand it, What I am trying to do is that I create a new Module and then on that module I call a view of `sale_order`, but I want to customize the view the way I want. Lets say the default view shows five coloumns and I want only two out of those five coloumns to be displayed. I tried some coding but it shows the default view. Here is my code. sale_order_duplicate_view.xml ----------------------------- sale.order.tree.inheritsale.orderSale Order Duplicatesale.order sale_order_duplicate.py ----------------------- from openerp.osv import fields,osv from openerp.addons.fleet.fleet import fleet_vehicle from openerp.osv.fields import _column class sale_order_duplicate(osv.osv): _inherit = 'sale.order' _description = "Sales Order" _columns = { } sale_order_duplicate() ----------------------- Can someone please tell me what else should I do and how this thing actually works. Thank you.