You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Melissa Campbell.

ASSISTANT: How may I guide you today?

USER: Please book a flight ticket from DCA to LGA for attend an interview.

ASSISTANT: Sure, I will help you with that. Can you please share your preferable journey dates?

USER: My journey dates are from Mar 22 to Mar 24.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: I am sorry to say that there is no flight found under your details.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for reaching us, have a great day.