XML : How to pass invisible for many2one field in following situation?

Here I have asset.asset inherited module in this field. I have one company_id1 which has A,B Value. If the selected company_id1 is B then 'manna_svg' should be invisible from the form.

  class asset_asset(osv.osv):      _inherit = "asset.asset"      #_name = "asset_asset"      _rec_name= "folio_num"      #_rec_name = "assetmodelid_add"      CRITICALITY_SELECTION = [          ('0', 'General'),          ('1', 'Important'),          ('2', 'Very important'),          ('3', 'Critical')      ]      _columns = {          'name': fields.char('Asset Name', size=64),          'numbers': fields.char('Numbers', size=64),          'company_id1': fields.many2one('res.company', 'Substation', required=True),          'tcomp': fields.char('Type of Substation'),          'bcomp': fields.char('Substation Belongs to'),            #'place1': fields.many2one('asset.parentlocation', 'Location'),          'asset_catg_id' : fields.many2one('asset.catg', 'Asset Catg ',select=True, required=True),              'area_id' : fields.many2one('asset.name', 'Asset Name ', domain="[('asset_catg_id', '=', asset_catg_id)]", select=True, required=True),          'assetmodelid_add' : fields.many2one('agile.portfolio1','Asset Model Code',domain="[('area_id', '=', area_id)]",),          'user_id': fields.many2one('res.users', 'Assigned to', track_visibility='onchange'),          'criticality': fields.selection(CRITICALITY_SELECTION, 'Criticality'),              'active': fields.boolean('Active'),          'folio_num' : fields.char('Folio No',),          'asse_line':fields.one2many('asset.line','emp_id','Name Plate'),          'asse_line2':fields.one2many('asset.part','emp_id1','Parts'),                 #'assed_modelid':fields.many2one('agile.portfolio1','Asset Model ID',select=True, required=True),          'quantity': fields.char('Quantity',size=64),          'uom': fields.char('Uinit of Measure',size=64),          'model_no' : fields.char('Model', size=64),          'msr_hour' : fields.one2many('hour.attr','hour_msr1','Inspection Attr',),          'manna_svg' : fields.many2one('svg.form','Single Line Diagram',)            #'asset_id':fields.many2one('agile.portfolio','Asset ID'),        }    

The following code is asset_view.xml file

  <xpath expr="//form/sheet/div/field[@name='name']" position="after">                      <group><field name="asset_catg_id"/>                        <field name="area_id" options="{'no_create': True, 'no_create_edit':True}"/>                      <field name="assetmodelid_add" on_change="get_asset_parts(assetmodelid_add)" options="{'no_create': True, 'no_create_edit':True}"/>                      <field name="company_id1" on_change="onchange_first_last(company_id1)" options="{'no_create': True, 'no_create_edit':True}"/>                      <field name="tcomp"/>                      <field name="bcomp"/>                      <!--<field name="model_no" on_change="get_asset_parts(assetmodelid_add)"/>-->                          <field name="folio_num" />                      <field name="criticality"/>                                      <field name="user_id" options="{'no_create': True, 'no_create_edit':True}"/>                      <field name="active"/>                      <field name="manna_svg" attrs="{'invisible':[('company_id1', '!=', '0')]}"/>                      </group>                    </xpath>