utf8.php

<?php 
/**
* 
*/
class Utf8
{
    
    function __construct()
    {
        global $CFG;
        if(
            preg_match('/./u', '') === 1
            AND function_exists('iconv')
            AND ini_get('mbstring.func_overload') != 1
            )
        {
            define('UTF8_ENABLED', TRUE);

            if(extension_loaded('mbstring'))
            {
                define('MB_ENABLED', TRUE);
                mb_internal_encoding('UTF-8');
            }
        }
    }

    function clean_string($str)
    {
        $str = @iconv('UTF-8', 'UTF-8//IGNOE', $str);
        return $str;
    }

    function convert_to_utf8($str, $encoding)
    {
        if(function_exists('iconv'))
        {
            $str = @iconv($encoding, 'UTF-8', $str);
        }
        elseif(function_exists('mb_convert_encoding'))
        {
            $str = @mb_convert_encoding($str, 'UTF-8', $encoding);
        }
        else
        {
            return FALSE;
        }

        return $str;
    }

    function _is_ascii($str)
    {
        return (preg_match('/[^x00-x7F]/S', $str)==0);
    }
}