I'm new to OpenErp. I want to Add a new field "mother_name" in res.partner.So i have added the following code to res.partner.py In column's i have add like this

_columns = {
    'name': fields.char('Name', size=128, required=True, select=True),
    'date': fields.date('Date', select=1),
    'title': fields.many2one('res.partner.title', 'Title'),
    'parent_id': fields.many2one('res.partner', 'Related Company'),
    'child_ids': fields.one2many('res.partner', 'parent_id', 'Contacts', domain=[('active','=',True)]), # force "active_test" domain to bypass _search() override    
    'ref': fields.char('Reference', size=64, select=1),
    'date_delivery': fields.date('Expected Delivery Date'),
    'mother_ln': fields.char('Mother', size=64),
     .
     .
     .
     }

Now in res_partner_view.xml . I'm using the following code

    <record id="view_partner_tree" model="ir.ui.view">
        <field name="name">res.partner.tree</field>
        <field name="model">res.partner</field>
        <field eval="8" name="priority"/>
        <field name="arch" type="xml">
            <tree string="Contacts">
                <field name="name"/>
                <field name="function" invisible="1"/>
                <field name="phone"/>
                <field name="email"/>
                <field name="user_id" invisible="1"/>
                <field name="is_company" invisible="1"/>
                <field name="country" invisible="1"/>
                <field name="country_id" invisible="1"/>
                <field name="date_delivery"/>
                <field name="mother_ln"/>
                <field name="parent_id" invisible="1"/>
            </tree>
        </field>
    </record>

<record id="view_partner_form" model="ir.ui.view"> <field name="name">res.partner.form</field> <field name="model">res.partner</field> <field eval="1" name="priority"/> <field name="arch" type="xml"> <form string="Partners" version="7.0"> <sheet> <field name="image" widget="image" class="oe_left oe_avatar" options="{"preview_image": "image_medium", "size": [90, 90]}"/>

                <group>
                    <group>
                        <label for="type" attrs="{'invisible': [('parent_id','=', False)]}"/>
                        <div attrs="{'invisible': [('parent_id','=', False)]}" name="div_type">
                            <field class="oe_inline"
                                name="type"/>
                        </div>

                        <label for="street" string="Address"/>
                        <div>
                            <field name="use_parent_address" class="oe_edit_only oe_inline"
                                   on_change="onchange_address(use_parent_address, parent_id)"
                                   attrs="{'invisible': [('parent_id','=', False),('use_parent_address','=',False)]}"/>
                            <label for="use_parent_address" class="oe_edit_only" attrs="{'invisible': [('parent_id','=', False),('use_parent_address','=',False)]}"/>
                            <button name="open_parent" type="object" string="(edit company address)" class="oe_link oe_edit_only"
                                    attrs="{'invisible': ['|',('parent_id','=', False),('use_parent_address','=',False)]}"/>
                            <field name="street" placeholder="Street..."  attrs="{'readonly': [('use_parent_address','=',True)]}"/>
                            <field name="street2"  attrs="{'readonly': [('use_parent_address','=',True)]}"/>
                            <div class="address_format">
                                <field name="city" placeholder="City" style="width: 40%%" attrs="{'readonly': [('use_parent_address','=',True)]}"/>
                                <field name="state_id" class="oe_no_button" placeholder="State" style="width: 37%%" options='{"no_open": True}' on_change="onchange_state(state_id)" attrs="{'readonly': [('use_parent_address','=',True)]}"/>
                                <field name="zip" placeholder="ZIP" style="width: 20%%" attrs="{'readonly': [('use_parent_address','=',True)]}"/>
                            </div>
                            <field name="country_id" placeholder="Country" class="oe_no_button" options='{"no_open": True}' attrs="{'readonly': [('use_parent_address','=',True)]}"/>
                        </div>

                    </group>
                    <group>
                      <!-- We Don't require Job Position for Customer -->
                      <!--   <field name="function" placeholder="e.g. Sales Director"
                            attrs="{'invisible': [('is_company','=', True)]}"/> -->
                        <field name="phone" placeholder="e.g. +32.81.81.37.00"/>
                        <field name="mobile"/>
                        <field name="fax"/>
                        <field name="email" widget="email"/>
                        <!-- <field name="title" domain="[('domain', '=', 'contact')]"
                            options='{"no_open": True}' attrs="{'invisible': [('is_company','=', True)]}" /> -->
                    </group>
                    <field name="date_delivery"/>
                    <field name="mother_ln"/>
                    </group>
                    .
                    .
                    .
             </record>