Hi Mohammed,

try this method for your button object:

  def button_function(self, cr, uid, ids, context):
        mod_obj = self.pool.get('ir.model.data')
        res = mod_obj.get_object_reference(cr, uid, 'complete_details (your module name)', 'complete_details_form_view (your_form_view_id)')
        res_id = res and res[1] or False
        return{
            'name':'Complete Details',
            'res_model':'complete.details',
            'type': 'ir.actions.act_window',
            'view_type': 'form',
            'view_mode': 'form',
            'view_id': [res_id],
            'context':{},
            'target':'new'
             }