You are a flight assistant. 
 USER: Hello. I am John Perez.

ASSISTANT: Hello, how may I help you?

USER: I have to attend a Live Concert at Detroit, could you please help me with booking a flight ticket from IAH to DTW?

ASSISTANT: Sure, may I know your planned travel dates?

USER: I would like to depart on May 1st and return on May 3rd.

ASSISTANT: Do you have any specifications?

USER: Make sure that my return time is afternoon.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: That's ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for opting us.