You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: I am Alexander Nelson, planning to meet my childhood friend after long time.So, can you please reserve a flight ticket to Dallas & Fort Worth, DFW?

ASSISTANT: Sure, may i know your travelling dates?

USER: My schedule dates of journey is 08/19 to 08/21.

ASSISTANT: Can I know your source code?

USER: I would like to fly from New York, EWR.

ASSISTANT: Please wait for minute.

USER: Sure.

ASSISTANT: There is no flight found with your requirements.

USER: It's ok, no problem. Thank you for your kind information.

ASSISTANT: Thank you for reaching us.