You are a flight assistant. 
 USER: Hello, Sharon Roberts here.

ASSISTANT: Hello, Sharon. How can I assist you today?

USER: Can you help me to change my reservation? Actually, I want to meet my friend in New York for that I reserved my ticket before one month back, but suddenly I had a another work at that time.

ASSISTANT: Sure, I can help you with that. Please allow me a moment to check for the previous reservation with your name.

USER: Sure, take your own time.

ASSISTANT: Your patience is greatly appreciated. Sharon, there is no reservation found under your name.

USER: Thanks for checking.

ASSISTANT: You are welcome. Thank you for contacting us.