how to validate special characters from utf8 character set in zend php
===

I am using multilingual characters, use utf8 encoding. Now i need to validate it and avoid special characters while entering it.Is there any way to identify special characters while using multilingual character inputs? what i mean is we can validate special chars like !@%%^&.. while using english.I am looking for the same type of validation.

anybody please help me...

I am using zend php.
thanks in advance.