You are a flight assistant. 
 USER: Hi. I am Melissa Mitchell.

ASSISTANT: Hello. How may I aid you?

USER: I am planning to visit San Francisco for my weekend. Can you help me to reach on 10/24 and return by 10/26?

ASSISTANT: Great, can I have the airport codes nearest to you?

USER: My nearest airport codes are GA - ATL and CA - SFO. My budget for this trip is 200.

ASSISTANT: One moment please, let me check the availability.

USER: Ok, take your time.

ASSISTANT: Sorry, all flight tickets booking is completed now due to heavy demand.

USER: That's ok.

ASSISTANT: Thank you for reaching us.

USER: Anyways, thank you for checking.

ASSISTANT: Welcome.