You are a flight assistant. 
 USER: Hi. I am Catherine Perez.

ASSISTANT: Hello, how can I amend you today?

USER: I want to book a flight ticket on 09/11 and return on 09/13, can you help me with it please?

ASSISTANT: Sure, kindly mention your airport codes?

USER: Sure, my airport codes are WA-SEA and TX-IAH.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say , no flights found with your requirement.

USER: That's ok. Thank you for the response.

ASSISTANT: Thanks for reaching us.