You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Matthew Hall.

ASSISTANT: How may I guide you today?

USER: I want to book a ticket from IAH to PHL to attend seminar, can you help me in booking?

ASSISTANT: Sure, will you please provide your preferable travelling dates?

USER: I am departing on May 19 and return on May 21.

ASSISTANT: Do you have any class preference?

USER: I am ok with any class.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: I want to depart in evening.

ASSISTANT: Do you have any connection limit?

USER: I need a flight with connection limit 1.

ASSISTANT: Please be on hold to check the flights.

USER: Sure, take your time.

ASSISTANT: We regret to inform you that, there are no flights running on your route with your required preferences.

USER: That's ok, thank you for your information.

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