You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Gregory King. I want to travel from TX-IAH to CA-LAX, can you please book a flight ticket?

ASSISTANT: Sure, could you help me with the travelling dates?

USER: My departure day is 01/27 and return day is 01/29.

ASSISTANT: OK. Give me a moment.

USER: OK.

ASSISTANT: Sorry for the inconvenience as there is no flight found matching your requirement.

USER: Thank you for your immediate response.