school/wizard/assign_roll_no_wizard.xml

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

        <!-- Assign Roll Number Wizard Form View  -->
        <record id="view_assign_roll_no_form" model="ir.ui.view">
            <field name="name">assign.roll.no.form</field>
            <field name="model">assign.roll.no</field>
            <field name="arch" type="xml">
                <form string="Assigning Roll Number">
                    <separator string="Assign Roll Number" colspan="4"/>
                    <group colspan="4" col="6">
                        <field name="standard_id" widget="selection" />
                        <field name="medium_id" widget="selection"  />
                        <field name="division_id" widget="selection" />
                    </group>
                    <separator string="" colspan="4"/>
                    <group colspan="4" col="6">
                        <label string="" colspan="2"/>
                        <button icon="gtk-cancel" special="cancel" string="Close"/>
                        <button icon="gtk-go-forward" name="assign_rollno" string="Finish" type="object"/>
                   </group>
               </form>
            </field>
        </record>

        <!-- Assign Roll Number Wizard Action  -->
        <act_window id="action_assign_roll_no_form"
            multi="True"
            key2="client_action_multi"
            name="Assign Roll Number"
            res_model="assign.roll.no"
            src_model="student.student"
            view_mode="form"
            target="new"
            view_type="form"/>

    </data>
</openerp>