Hi Behzad, I would try a different approach ... EXAMPLE (UTF-8): <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>Persia</title></head><body><?php$username = '1aﺠﺟﺝﭻﭽﭼﭺ2b;$encoding = 'utf-8';$username = mbStringToArray($username, $encoding);foreach($username as $char) { if (strlen($char) == 1) echo $char.' is not a multibyte character<br />';}function mbStringToArray ($string, $encoding) { $strlen = mb_strlen($string); while ($strlen) { $array[] = mb_substr($string,0,1,$encoding); $string = mb_substr($string,1,$strlen,$encoding); $strlen = mb_strlen($string); } return $array;}?></body></html> As you can see I'm using the multibyte string functions [1] and split$username into a character by character array.Then I use strlen() for which an UTF-8 char has a length > 1. Note:This might change with PHP6.It also does not check for Persian characters only yet. You would haveto try something like this ... EXAMPLE (UTF-8): <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>Persia</title></head><body><?php$username = '1aﺠﺟﺝﭻﭽﭼﭺ2b';$encoding = 'utf-8';$chars = 'ﺐﺒﺑﺏﭗﭙﭙپﺖﺘﺗﺕﺚﺜﺛﺙﺞﺠﺟﺝﭻﭽﭼﭺﺢﺤﺣﺡﺦﺨﺧﺥﺪﺪﺩﺩﺬﺬﺫﺫﺮﺮﺭﺭﺰﺰﺯﺯﮋﮋژژﺲﺴﺳﺱﺶﺸﺷﺵﺺﺼﺻﺹﺾﻀﺿﺽﻂﻄﻃﻁﻆﻈﻇﻅﻊﻌﻋﻉﻎﻐﻏﻍﻒﻔﻓﻑﻖﻘﻗﻕﮏﮑﮐکﮓﮕﮔگﻞﻠﻟﻝﻢﻤﻣﻡﻦﻨﻧﻥﻮﻮووﻪﻬﻫﻩﯽﻴﻳﻯ';$username = mbStringToArray($username, $encoding);foreach($username as $char) { if (strlen($char) == 1) echo $char.' is not a multibyte character<br />'; if (mb_strpos($chars, $char, 0, $encoding) !== false) echo $char.' isa Persian character<br />';}function mbStringToArray ($string, $encoding) { $strlen = mb_strlen($string); while ($strlen) { $array[] = mb_substr($string,0,1,$encoding); $string = mb_substr($string,1,$strlen,$encoding); $strlen = mb_strlen($string); } return $array;}?></body></html> [1] http://in.php.net/manual/en/ref.mbstring.php[2] http://in.php.net/manual/en/function.strlen.php
