You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you?

USER: I want to reserve my ticket from CLT to IAH, can you please help me in booking?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: Sure, my planned dates of journey are from Apr, 04 to Apr, 06.

ASSISTANT: Do you have any preferences?

USER: Yes, I want to travel in a economy class.

ASSISTANT: May I know your name please?

USER: Sure, my name is Gregory Hall.

ASSISTANT: Sorry, there is no flight available with your requirements.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: You are welcome, have a nice day.