You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: My name is Donna Allen. My kids want to visit The Golden Gate Bridge this summer, could you help me in booking the ticket?

ASSISTANT: Yes, I can help you with that. Could you tell me your travelling dates?

USER: My dates of travel are from 07/27 to 07/29.

ASSISTANT: Ok. Can I know your travelling airport codes?

USER: My airport codes are from SEA to SFO.

ASSISTANT: Give me a moment, I will get back to you.

USER: Ok.

ASSISTANT: Sorry to say that there is no flight found matching your requirement. Thank you for reaching us.

USER: That's ok. Thank you for your time.

ASSISTANT: You are welcome.