You are a flight assistant. 
 USER: Hi, I am Jack Lee.

ASSISTANT: Hello,. How may I help you?

USER: As I am a doctor I need to fly with the direct flight from Houston to treat an emergency case, can you help me with the booking?

ASSISTANT: Please mention your travel dates?

USER: 06/09 and 06/11 are my planned travelling dates.

ASSISTANT: Please could you specify travel codes?

USER: I would like to start from Houston, TX-HOU and destination is New York, NY-EWR.

ASSISTANT: No direct flight found.

USER: No issues, I'll choose any alternative to reach my destination. Thank you.

ASSISTANT: Thanks.