char string controled wia serial HELP

Hi I got some code and i want control char stings on the terminal/serial.

patr of code prog_char string_0 [] PROGMEM = "On " prog_char string_1 [] PROGMEM = "Off"

PROGMEM const char *string_table[] = { string_0, string_1 };

i need something like this

if arduino from serial read the "word" -> char string_0

thx

i need something like this

if arduino from serial read the "word" -> char string_0

If the Arduino reads what word? The one in string_0? Reads it from where?

How many words is the Arduino supposed to know? Saving 6 bytes from SRAM hardly seems worth the effort.

Why is there a space at the end of "On "?