You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to book a ticket from DCA to MCO?

ASSISTANT: Sure, can I know your travel dates?

USER: My planned dates of journey are Dec 29 and Dec 31 respectively.

ASSISTANT: Noted. Please let me know your class preference.

USER: There is no class specifications.

ASSISTANT: Ok, may I know your name?

USER: My name is David Scott.

ASSISTANT: Thank you. Please wait for a while, I will check for the available flights and let you know.

USER: Ok, please take your own time.

ASSISTANT: Sorry, there is no flight available on your given travel dates.

USER: That is ok, thank you for assisting me.

ASSISTANT: You are welcome.