Php-is there a problem with PHP verifying user names? Zhang Sizhong's

Regular PHP

Basic can, but this does not, the user name replaced Zhang San OK, why? Newbie's pain, thank you.

 
   
   \'\"\\ 　]/';    if(preg_match($_char_pattern,$_string)){        echo '用户名不得包含敏感字符！';    }else{        echo '没有敏感字符';    }?>

Supplement 1:

Replies to the answer:
The blank place is 2 spaces, one half-width, one full-width

\s Use this can be passed, the use of separate half-width space can also be OK, plus full-width filter Zhang Sizhong's.

I just learned, this is really not understand;

Thanks for the answer, I hope it can be solved.

Supplement 2:

JS authentication can be done by Zhang Sizhong's!

    if(/[<>\'\"\ 　]/.test(fm.username.value)){            alert("用户名包含非法字符");            fm.username.focus();            return false;                   }

