string wont compile? - bizzarre behaviour!

Ive encountered the most bizarre scripting issue ever. Ive made a string and it will stop any script from compiling, even a newly made one. I have NO fricken idea whats wrong with it. the subject guilty of causing my head troubles is here:

string helptext = "Copy this list into the Presets Notecard inside the root prim of your avatar´s head, replacing one of the 3 lines. Do NOT add any lines, it will have no effect!";

this string will NOT compile, there will be a "syntax error" right after "Copy" - if I delete it, it will be after "this", and so on, until the string has lost about 80% of its length - then it will compile. since I cant affort to cut up the string like this, and since this seems to be very well inside the 255 char limit (I can write it into mainchat no problem), there must be something very very very wrong.

any help is greatly appreciated, since this really is bugging me out

Try replacing avatar's with avatar\'s

Might be something with the '

that actually was the cause, many thanks to you!

I've had trouble with strings copied from word documents. Something about certain characters not actually being the characters they appear to be.

yes your is a ´
which may not be valid unlike '
and then there is `

all different