Sorry.... would it be possible to add comments to each of the following lines:

You have to make your own subroutine to compare byte to byte the two string array. Like that:

i=0
while i less_than gsmbuffer_length (I cant sen the less character! Why?)

if gsmbuffer[i]=compare_array[i] then
'gsmbuffer[i]=0
i=i+1
else
goto wrong_sms
endif
wend
correct_sms:
'your code here

wrong_sms:
'your code here

Could you give me an example using the SMS keyword: "switch on" in order to switch on an LED.

Thanks again.

Regards,
Royce