detecting 2-bit characters.

Hello, Our submission form is being submitted 30% by Japanese nationals and they (stupidly even if we mention it) write their data in Japanese instead of English. (the product and the whole website is in English). It is now to time to disallow it. q: How can I detect if a string is contains over 1-bit characters ? I do have an idea how to write this kind of thing but I was wondering if there's a build-in function in PHP. Anyone used/wrote anything like this? Just to detect this for me is enough. Thanks, it would save lots of my time. Maxim Maletsky - maxim@j-door.com <mailto:maxim@j-door.com> Webmaster, J-Door.com / J@pan Inc. LINC Media, Inc. TEL: 03-3499-2175 x 1271 FAX: 03-3499-3109 http://www.j-door.com <http://www.j-door.com/> http://www.japaninc.net <http://www.japaninc.net/> http://www.lincmedia.co.jp <http://www.lincmedia.co.jp/>