[Autocomplete] Using UTF-8 encoding and local data javascript - matching fails

[Autocomplete] Using UTF-8 encoding and local data javascript - matching fails

Hello,
I'm using Jorn's Autocomplete plugin for Greek language. My data is dumped to a local file 'localdata.js' from the database and then the autocomplete matches strings to that data (as in the example with the email matching...). Both me database and my HTMLs are in UTF-8, and although my data is printed well in my webpage, no match is made to the greek strings. Strings in English are matched perfectly, but no matching can be made with the greek ones.
What should I do? Is it a javascript problem?
Thank you !