You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Ruth Thomas here.

ASSISTANT: How can I assess you?

USER: Due to sudden change in my planned date of journey, I would like to change my reservation. Can you please help me out with that?

ASSISTANT: Sure, I am glad to help you in that one. Please give me a moment to check your previous ticket booking in our list.

USER: Thank you for taking my request, take your time.

ASSISTANT: Thank you for waiting, there is no reservation found for the user name in our list when I have checked to help you out in ticket modification.

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: I think it might be happened and thank you for reaching us, have a nice day.

USER: Welcome.