You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sarah Mitchell.

ASSISTANT: What assistance do you need from us?

USER: Can you assist me in flight ticket reservation on 05/23 and return ticket on 05/25?

ASSISTANT: Sure, I will help you. Can you please provide me your travel airport codes?

USER: Thank you and my regional airport codes are to LGA from EWR.

ASSISTANT: Ok, please wait a minute.

USER: Sure, take your time.

ASSISTANT: Sorry to inform you, there is no flight available with the dates you have given.

USER: Ok, that's fine. Thank you for your help.

ASSISTANT: You are welcome.