hello , i need to book a ticket going to cambridge arriving by 16:30 , can you help me with that ? i am departing from broxbourne on friday .
there are a lot of trains available . where are you departing from ?
{'service': 'train', 'act': 'inform', 'slot_name': 'id', 'value': 'tr2145'}
tr2145 looks like it will get you there with plenty of time to spare .