You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Barbara Carter here.

ASSISTANT: How may I help you?

USER: In April, I have planned to meet my cousin. Can you book my ticket from EWR to LAX?

ASSISTANT: Yes sure. Could you help me with your travelling dates?

USER: My travelling dates are from 04/21 to 04/23.

ASSISTANT: Sorry, there is no flight with your details.

USER: It's ok. Thank you to visit us.

ASSISTANT: Welcome.