Do you know who am I

One guy was selected as a Trainee Clerk to a private company.
On his first day of work, in the afternoon he thought of ordering one coffee for himself. He called the pantry extension and said, "Please send one coffee."
The person from the other end: "What?"
Clerk: "Send me one coffee immediately."
The person from the other end: "Idiot, do you have any idea where you have dialled the number?"
Clerk, hesistating a little: "Pantry, of course."
The person from the other end fuming now said angrily: "This extension is for the managing director of the company and I am the Managing Dirctor."

After a few seconds the clerk said loudly, "And do you know who I am?"
Managing director" No..."
Clerk, "Thank God!"

and he kept the phone.