You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Shirley Hernandez here.

ASSISTANT: How may I serve you?

USER: Can you please reserve a flight ticket from BOS to DTW for my business trip?

ASSISTANT: Sure, I will help you in flight ticket reservation?

USER: Thank you.

ASSISTANT: May I know your travel dates please?

USER: I am planning to leave on 12/26 and please book my return ticket on 12/28.

ASSISTANT: Please wait for a minute, while I am checking for the flights available.

USER: Ok, take your time.

ASSISTANT: Thanks for your time Shirley.

USER: It's alright.

ASSISTANT: But I am sorry to say that presently there are no flights available with us.

USER: Oh! So sad to hear that. Anyway, I will go with another alternative. Thank you for the information.

ASSISTANT: Thank you.