You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I am Mark Hernandez, planning to go for holiday trip. I want you to help me in reserving my ticket to IAD.

ASSISTANT: Sure, may I know your travelling dates?

USER: I am planning on 03/23 to 03/25.

ASSISTANT: To provide booking I need your source code.

USER: SFO is my origin.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no flights found on your given requirements.

USER: Ok, Thanks for sharing information to me.

ASSISTANT: Thank you have a joyful day.