odoo/addons/crm/wizard/crm_lead_to_opportunity_view.xml

<openerp>
      <data>

        <record id="view_crm_lead2opportunity_partner" model="ir.ui.view">
          <field name="name">crm.lead2opportunity.partner.form</field>
          <field name="model">crm.lead2opportunity.partner</field>
          <field name="type">form</field>
          <field name="arch" type="xml">
               <form string="Convert to Opportunity">
                    <group width="540" height="400">
		                <label string="Are you sure you want to create a partner based on this lead ?" colspan="4"/>
		                <label string="You may have to verify that this partner does not exist already." colspan="4"/>
		                <group colspan="4" col="1" attrs="{'invisible':[('msg','=',False)]}">
		                    <field name="msg" colspan="4" nolabel="1" height="50"/>
		                </group>
		                <newline />
		                <field name="action"/>
		                <group attrs="{'invisible':[('action','!=','exist')]}">
		                    <field name="partner_id" attrs="{'required': [('action', '=', 'exist')]}"/>
		                </group>
		                <separator string="Convert to Opportunity" colspan="4"/>
		                <field name="name" colspan="4"/>
		                <group col="4" colspan="4" attrs="{'invisible': [('name', '=', 'convert')]}">
		                    <separator string="Select Opportunities" colspan="4"/>
		                    <field name="opportunity_ids" colspan="4" nolabel="1" height="130"/>
                        </group>
		                <separator string="" colspan="4" />
		                <group col="4" colspan="4">
		                    <button special="cancel" string="Cancel" icon="gtk-cancel"/>
		                    <button name="action_apply" string="Create Opportunity" type="object" icon="gtk-ok"/>
		                </group>
		          </group>
              </form>
          </field>
       </record> 

     </data>
</openerp>