You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am Melissa Johnson. Please book me a ticket from DCA to SFO to meet my family.

ASSISTANT: Sure, may I know your travelling dates?

USER: I have planned to travel on Mar 09th and return on Mar 11th.

ASSISTANT: Do you need any class preference?

USER: No.

ASSISTANT: Can I know your depart and return timing?

USER: My depart and return should be in the morning.

ASSISTANT: Sorry, there are on flights available.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.

USER: Thank you.