You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am planning to visit San Francisco, can you please book me a ticket from IAH to SFO?

ASSISTANT: Sure, kindly share your travel dates.

USER: I am planning my journey on the dates of Dec 23 and Dec 25.

ASSISTANT: Please wait a minute.

USER: Please ensure that departing flight is in the afternoon time.

ASSISTANT: Sorry, there are no flights available on your required routes.

USER: Ok, not an issue. I will find any alternate for this trip.

ASSISTANT: May I know your name please?

USER: My name is Rachel Williams. Thank you for providing information.

ASSISTANT: Thank you for choosing us.