You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you today?

USER: Can you help me to book a connecting flight?

ASSISTANT: Sure, may I know your airport codes please?

USER: My airport codes are SEA and IAD.

ASSISTANT: When do you like to travel?

USER: My travelling dates are 12/30 and 01/01.

ASSISTANT: Please share me your name.

USER: My name is David Hill.

ASSISTANT: Do you have any specifications?

USER: No.

ASSISTANT: Sorry, there is no flight on your details.

USER: No issues, thank you for your response.

ASSISTANT: Thank you.