[avr-gcc-list] zero byte in c

[Ryder Saint]

Dear List

how can i write this so a zero byte is attached to the end of it

prog_char banner_P[] = "<MESSAGE>Hello World</MESSAGE>";

someone suggested that I add ( chr$(0) ) to the end of the line but i
have no idea what he meant 
sorry i am a real newbie to c

Your Sincerely 

Ryder Saint

Watanabe Giichi Seisakusho
Kyoto, Japan