You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Mary Jackson this side, I am looking to modify the dates of my previous reservation. Can you please help me?

ASSISTANT: Ok, I will help you out in changing reservation.

USER: Thank you.

ASSISTANT: I have found your reservation, please help me with your new airport codes?

USER: I am looking to travel from ORD to LGA.

ASSISTANT: Sure, please wait a moment. Can you please provide me your travelling dates?

USER: My dates of journey are 04/09 and 04/11.

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there are no flights found.

USER: Ok, no issues. I will go by road.

ASSISTANT: Thanks for choosing our services. Have a nice day.

USER: Thank you for helping me.