I use pdf_findfont function for writing text in a pdf document, ok? I call the function like this:

PHP Code:
$arial pdf_findfont$pdf"Arial""host" ); 
You see the third argument? "host" I mean, I saw this argument in all the examples and source codes (including php documentation itself ). As the documentation says this is the 3rd argument which defines the encoding. So, I replaced "host" with "utf-8" and it gave me this error message:

PDFlib error: Resource configuration file 'pdflib.upr' not found
What does it mean? How should I fix it? I really need to write utf-8 in my PDF files.

Many thanks in advance