I suggest to use llSetNotecard instead.
LindenLab has refused on many occasions over the years to implement any function that results in writing or changing the contents of notecards. The reason given for this is that under the current implementation, when notecards are changed, a new asset is created, which is perfectly logical as they don't know how many copies of a notecard exist (updating one copy should not update all copies). The alternatives are to use script memory or offsite storage via Email, XML-RPC or HTTP. -- Strife Onizuka 16:18, 27 July 2007 (PDT)