You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your help?

USER: I am Donald Green. Can you please help me in booking a flight ticket from ORD to EWR?

ASSISTANT: Sure, please provide me your planned travel dates.

USER: I would like to fly on July 16 and return on July 18.

ASSISTANT: Do you prefer any specific airline?

USER: I am comfortable with any airline.

ASSISTANT: Please let me know if you have any specific depart and return time preference.

USER: I would like to depart in morning time.

ASSISTANT: Do you prefer either economy or business class?

USER: I am comfortable with any class.

ASSISTANT: Please let me know if you have any other preference.

USER: No, I don't have any other preference.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: Not an issue. Thank you for your information.

ASSISTANT: Thank you.