You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: My name is Brian Walker.

ASSISTANT: Nice to meet you.

USER:  I am planning to travel from SFO to IAH to attend my sister's wedding, could you please help me with booking a flight ticket?

ASSISTANT: Ok. May I know your travelling dates?

USER: My preferable dates are from 12/09 to 12/11.

ASSISTANT: Please hold on. There is no flight available with your details. Sorry for inconvenience. Thank you for choosing us, have a nice day.

USER: That's ok. Thank you for your time.