Permission denied

[yzzzzz]

Hi,

I am writing a script (in JavaScript) for Mozilla, that will stay on my 
hard drive. When trying to access other documents, I get this error:

Error: uncaught exception: Permission denied to get property 
HTMLDocument.getElementsByTagName

Is there anyway I can specify that this particular script is safe? Can I 
tell Mozilla that it is in a 'safe zone' or on a 'trusted site'?

Thanks.

(fu2)