Hi, i want to inherit the view partenariat described in the bellow code, and add to it 3 fields

<record model="ir.ui.view" id="partenariat_form"> 
    <field name="name">partenariat.form</field> 
    <field name="model">partenariat</field> 
    <field name="type">form</field> 
    <field name="arch" type="xml">
     <form string="Formulaire partenariat" version="7.0" > 
        <sheet>
           <group col="2" string="Gestion des Partenariats">

            <field name="sujet"/> 
            <field name="organisateur"/>
            <field name="lieu"/> 
            <field name="date_debut"/>
            <field name="date_fin" /> 
          </group>
          </sheet>
        </form>
    </field>
</record>

i wirite the code of the salon view who inherit from patenariat view like bellow:

<record model="ir.ui.view" id="salon_form"> 
    <field name="name">salon.form</field> 
    <field name="model">salon</field> 
    <field name="type">form</field> 
    <field name="inherit_id" ref="partenariat_form"/>  
    <field name="arch" type="xml">
    <xpath expr="/form/sheet/group/field[@name='date_fin']" position="after">
                    <field name="prix_par_metre_salon" widget="integer"/>
                    <field name="espace_reserve_salon" widget="integer"/> 
                    <field name="cout_total_salon" widget="integer"/>
            </xpath>  

    </field> 
</record>

i was succeed to inherit fields, but i dont have a good result because my salon view is not in a sheet and don't have a title, i want that my salon views in a sheet, i try t add sheet balise but also no changes, plz help me