This is my code: 

import openerpfrom openerp.osv 
import osv,fieldsfrom datetime 
import dateclass tickets(osv.Model):    
    _name = 'tickets'    
    _inherit = ['mail.thread']    
    _rec_name = 'code'    
    
? -->
    def _connect_tickets(self, cr, uid, ids, context=None):        
        print context        
        return False    
<--?

    _columns = {        
        'code': fields.char(string='Reference'),        
        'title': fields.char(string='Title', required=True),        
        'description': fields.text(string='Description', required=True),        
        'partner_id': fields.many2one('res.partner', string='Partner', required=True),        
        'responsible_id': fields.many2one('res.users', string='Responsible'),        
        'channel_id': fields.many2one('crm.tracking.medium', string='Channel'),        
        'email_from': fields.char(string='From:'),        
        'email_cc': fields.char(string='CC:'),        
        'date': fields.date(string='Date'),        
        'write_date': fields.date(string='Update date'),        
        'date_deadline': fields.date(string='Deadline date'),        
        'date_closed': fields.date(string='Closed date'),        
        'priority': fields.selection([('0', 'Low'), ('1', 'Normal'), ('2', 'High')], string='Priority'),        
        'status': fields.selection(            
            [('draft', 'New'),             
            ('open', 'In Progress'),             
            ('pending', 'Pending'),             
            ('validate', 'To Validate'),             
            ('done', 'Closed'),             
            ('cancel', 'Cancelled')], string='Status', required=True),        
        'ref': fields.char(string='Reference', selection=openerp.addons.base.res.res_request.referencable_models),        
        'ref2': fields.char(string='Reference 2', selection=openerp.addons.base.res.res_request.referencable_models),        
        'spent_time': fields.float(string='Spent time'),        
        'is_email': fields.boolean(string='is_email'),        
        'parent_ticket_id': fields.many2one('tickets', string='Related tickets'),        
        'child_ticket_ids': fields.one2many('tickets', 'parent_ticket_id', compute='_connect_tickets', string='Related tickets'),        
        'registers_ids': fields.one2many('registers', 'tickets_id', string='Registers'),        
        'fused': fields.selection([('fused', 'Fused')], string='Status'),    
    }

What I want is when I add a ticket in child_ticket_ids field, the ticket associated has the ticket where I associate it. 

For example: 

I have ticket #001 and in the form view (in the child_ticket_ids field) I associate ticket #002, when I do this I want the ticket #002 has in its child_ticket_ids field ticket #001.