You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Myself Catherine Scott here. I want to travel from CA-OAK to TX-IAH, to visit Houston, can you please help me to book a ticket?

ASSISTANT: Sure, can you help me with your planning dates?

USER: Sure, my preferable dates are from 04/28 to 04/30.

ASSISTANT: Thank you for your information. Sorry. There is no flight is available for your details.

USER: No issues. Thank you for your service.

ASSISTANT: Welcome.