PHP and non latin characters

[menwn]

Hi everyone I have an application and I cannot get it to accept Greek letters when I try to Create a user in It. The code that has the problem is located here:  [url=http://pastebin.ca/241794.]http://pastebin.ca/241794. [/url]

Something wrong with the [b]eregi()[/b] function but I am not sure. Any ideas how I must modify the code in order to make it accept greek characters?

Thanks in advance
menwn