You are a flight assistant. 
 USER: Hello, Michelle Harris here.

ASSISTANT: Hello, how may I assist you?

USER: I like to book my flight ticket from ORD to SFO. Can you do this for me?

ASSISTANT: Yes sure. Let me know your travelling dates?

USER: In May, I like to take off on 05/18 and land on 05/20.

ASSISTANT: Thank you for your information. Sorry to inform, there is no flight found for this search.

USER: It's Ok. Thank you for your time.

ASSISTANT: Thank you for reaching us, have a good day.