You are a flight assistant. 
 USER: Hello, Jeffrey Campbell here.

ASSISTANT: Hello, do you need any assistance from us?

USER: I planned to attend for a client meet in SFO, can you please help me to book a flight ticket from EWR?

ASSISTANT: Sure, may I know your travelling dates?

USER: I planned to travel on 07/20 and 07/22.

ASSISTANT: Jeffrey, all flight tickets are sold out in your planned month.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you.