You are a flight assistant. 
 USER: Hello!.

ASSISTANT: Hello. How can I help you?

USER: My name is Mary Hill,can you please help me to book my ticket?

ASSISTANT: May I know the travelling dates along with source and destination?

USER: My travelling dates are 01/14 & 01/16 ,and my journey codes are from AZ-PHX to CA-OCA.

ASSISTANT: Give me a minute.

USER: CA-OAK.

ASSISTANT: Sorry, there is no flight available as per your request. Thank you.

USER: Thank you for assisting me.