i am looking for a train please .
user
there are several trains where are you going ?
assistant
i am going to cambridge from leicester . i am planning to leave on sunday and i need to be there by 11:45 .
user
if you take the tr1079 at 9:09 you can arrive in cambridge by 10:54 . would you like me to book it ?
assistant
yes , that sounds great . i would like to book the train for 7 people . what is the reference number ?
user
there is the reference number tr4106
assistant
thank you for your help
user
thank you for using our services . do you need any further assistance ?
assistant
that is all i needed . thank you .
user
you are welcome . have a nice day and please call us again !
assistant
wait , i do not think that s a valid reference number .