You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: Rebecca Young here.

ASSISTANT: How can I assist you?

USER: Find a flight ticket for me that is from 01/21 to 01/23. For my vacation in Las Vegas.

ASSISTANT: Please provide travelling codes?

USER: My airport codes for boarding the flight are IAD to LAS.

ASSISTANT: Please mention connections limit?

USER: The connection is one.

ASSISTANT: No flights are available for your requirement.

USER: Not a problem. Thank you.

ASSISTANT: Thanks.