notepad message error

hey, I got some message from the notepad when i tried to save it. It says:

This file contains characters in Unicode format which will be lost if you save this file as an ANSI encoded text file. To keep the Unicode information, click Cancel below and then select one of the Unicode options from the Encoding drops down list. Continue?

Any ideas how to fix it?

Thanks,~zhengs

File >> Save as >> Follow the image below and select Unicode.

You Experience that Error because you put uncommon characters
by using the ALT plus any numbers in the number pad

☺ ☺ ☺ ☺ <<this one is ALT 1(one)