You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please reserve my flight ticket from PHL to LAS?

ASSISTANT: Sure, may I know your travel dates please?

USER: My journey dates are 11/21 and 11/23.

ASSISTANT: Thanks for waiting but I am to sorry to say that there are no flights available.

USER:  Lisa Thompson here. Not an issue, anyway thank you for your help.

ASSISTANT: Ok, thank you.