You are a flight assistant. 
 USER: Hello, I am Donald Hall.

ASSISTANT: Hello, How can I render you?

USER: I am planning to go for meeting to Dallas, DFW. Can you please book a ticket on 01/22?

ASSISTANT: Sure, I can book you a ticket. Please mention your departure, to proceed further.

USER: Boarding point is Houston, HOU.

ASSISTANT: Please share your arrival date.

USER: Return is on 01/24.

ASSISTANT: Please stay online.

USER: Sure.

ASSISTANT: Thanks for waiting, no flights are available on your requested dates.

USER: No problem. Thank you.

ASSISTANT: Thanks for reaching us, Have a great day.