http ://pl.php.net/manual/en/function.ereg.php

注意:从PHP 5.3.0开始，不赞成使用regex扩展名，而推荐使用PCRE扩展名.调用此函数将发出E_DEPRECATED通知.请参阅差异列表，以获取转换为PCRE的帮助.

Note: As of PHP 5.3.0, the regex extension is deprecated in favor of the PCRE extension. Calling this function will issue an E_DEPRECATED notice. See the list of differences for help on converting to PCRE.