on change method in openerp

Question

i am trying onchange method programme in openerp using python. but there is no error at the same time there is no response while i change name in field.

xml coding (cus_view.xml)

<?xml version="1.0"?>
<openerp>
<data>

<!-- ===================== This is tree layout =============================-->

<record model = "ir.ui.view" id = "custom_tree">
    <field name = "name">Custom</field>
    <field name = "model">cus.custom</field>
    <field name = "type">form</field>
    <field name = "arch1" type = "xml">
        <tree string = "custom" version = "7.0">
            <field name = "name"/>
            <field name = "customer_name"/>
            <field name = "customer_street1"/>
            <field name = "customer_street2"/>
            <field name = "customer_city"/>
            <field name = "customer_state"/>
            <field name = "customer_zip"/>
            <field name = "customer_country"/>
            <field name = "customer_mobile"/>
            <field name = "customer_mail"/>
        </tree>
    </field>
</record>

<!-- ========================This is Form layout===============================-->

<record model = "ir.ui.view" id = "custom_form">
    <field name = "name">Custom</field>
    <field name = "model">cus.custom</field>
    <field name = "type">form</field>
    <field name = "arch1" type = "xml">
        <form string = "custom" version = "7.0">
            <label for = "name" string = "Lab Id"/>
            <field name = "name" style = "width:10%%" /><br/>

            <label for = "customer_name" string = "Customer Name" />
            <field name = "customer_name" style = "width:10%%" on_change="on_change_customer(customer_name)" /><br/>

            <label for = "Street1" string = "Address"/>
            <field name = "customer_street1" style = "width:10%%"/><br/>
            <field name = "customer_street2" style = "width:10%%"/><br/>
            <field name = "customer_city" style = "width:10%%"/><br/>
            <field name = "customer_state" style = "width:10%%"/><br/>
            <field name = "customer_zip" style = "width:10%%"/><br/>
            <field name = "customer_country" style = "width:10%%"/><br/>
            <label for ="customer_mobile" string = "Mobile"/>
            <field name = "customer_mobile" style = "width:10%%"/><br/>
            <label for ="customer_mail" string = "Email"/>
            <field name ="customer_mail" style = "width:10%%"/>
        </form>
    </field>
</record>

<!-- ========================= Action Layout ============================= -->

<record model = "ir.actions.act_window" id = "action_custom">
    <field name = "name">Custom</field>
    <field name = "res_model">cus.custom</field>
    <field name = "view_type">form</field>
    <field name = "view_mode">tree,form</field>
</record>

<!-- ===========================Menu Settings=========================== -->

<menuitem name = "Lab Information" id = "menu_cus_custom" action = "action_custom"/>

</data>
</openerp>

python coding (cus.py) from osv import osv from osv import fields

class cus(osv.osv):

    _name = "cus.custom"
    _description = "This table is for keeping personal data of student"
    _columns = {
        'name': fields.char('Lab Id',size=64,required=True),
        'customer_name': fields.many2one('res.partner', 'Customer'),
        'customer_street1': fields.char('Street', size=64),
        'customer_street2': fields.char('Street', size=64),
        'customer_city': fields.char('City', size=64),
        'customer_state': fields.char('State', size=64),
        'customer_zip': fields.char('Zip', size=64),
        'customer_country': fields.char('Country', size=64),
        'customer_mobile': fields.char('Mobile', size=64),
        'customer_mail': fields.char('Mail', size=64)
    }

def on_change_customer(self, cr, uid, ids, customer_name, context=None):
    values = {}
    if customer_name:
        cust = self.pool.get('res.partner').browse(cr, uid, customer_name, context=context)
        values = {
            'customer_country': cust.name
        }
    return {'value' : values}

Answer 1

update your xml file, no need to write label for each, try this 

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

    <!-- ===================== This is tree layout =============================-->

    <record id="custom_tree" model="ir.ui.view">
            <field name="name">Custom</field>
            <field name="model">cus.custom</field>
            <field name="arch" type="xml">
                <tree string="custom">
                    <field name = "customer_name"/>
                    <field name = "customer_street1"/>
                    <field name = "customer_street2"/>
                    <field name = "customer_city"/>
                    <field name = "customer_state"/>
                    <field name = "customer_zip"/>
                    <field name = "customer_country"/>
                    <field name = "customer_mobile"/>
                    <field name = "customer_mail"/>
                </tree>
            </field>
        </record>
<!-- ========================This is Form layout===============================-->
    <record id="custom_form" model="ir.ui.view">
            <field name="name">cus.custom</field>
            <field name="model">cus.custom</field>
            <field name="arch" type="xml">
                <form string="custom" version="7.0">
                    <label for="name" class="oe_edit_only"/>
                    <h1><field name="name"/></h1>
                    <group>
                        <field name = "customer_name" on_change="on_change_customer(customer_name)"/>
                        <field name = "customer_street1"/>
                        <field name = "customer_street2"/>
                        <field name = "customer_city"/>
                        <field name = "customer_state"/>
                        <field name = "customer_zip"/>
                        <field name = "customer_country"/>
                        <field name = "customer_mobile"/>
                        <field name = "customer_mail"/>
                    </group>
                </form>
           </field>
        </record>


    <!-- ========================= Action Layout ============================= -->

        <record id="action_custom" model="ir.actions.act_window">
            <field name="name">Custom</field>
            <field name="type">ir.actions.act_window</field>
            <field name="res_model">cus.custom</field>
            <field name="view_type">form</field>
            <field name="view_mode">tree,form</field>
            <field name="view_id" ref="custom_form"/>

        </record>

    <!-- ===========================Menu Settings=========================== -->

        <menuitem name = "Lab Information" id = "menu_cus_custom" action = "action_custom"/>
</data>
</openerp>

Answer 2

You have wrote onchange on label because of that its not responding. Try this,

<label for = "customer_name" string = "Customer Name"/>
<field name = "customer_name" onchange="on_change_customer(customer_name)" style = "width:10%%"/><br/>

There is one another mistake you have made, improve field name in tree view,

<field name = "customer_country"/>

This will work.