You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Jeffrey Jackson here, I want to go OAK from SFO. Can you book my ticket?

ASSISTANT: Sure, will you provide your travelling dates?

USER: In January, I like to go on 01/18 and return will be 01/21.

ASSISTANT: Unfortunately there is no flights found for your required details.

USER: It's ok. Thank you.

ASSISTANT: Thanks for reaching us.Have a nice day.