You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Melissa Turner here.

ASSISTANT: How may I help you?

USER: In the last month I have reserved a flight on my name to travel to Charlotte to celebrate my father birthday but suddenly there is an examination on the same date our college management has informed suddenly to us. So I will travel to my home on some other dates. Can you please help me in changing my flight ticket booking?

ASSISTANT: Sure, I am happy to help you.

USER: Thank you.

ASSISTANT: Yes Turner, your reservation is found, may I know your travelling dates?

USER: Sure, I am planning to move on 08/19 and please book my return ticket on 08/21.

ASSISTANT: Ok, can I know your airport codes?

USER: Sure, I want to travel from JFK to CLT.

ASSISTANT: Ok, wait for a second.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: Oh! So sad to hear that.

ASSISTANT: Thank you for reaching us.

USER: Anyway, thank you for the information.