/**
  * @param string $from_encoding
  * @param string $to_encoding
  * @param string $str
  * @return string
  */
 function ClassIconv($from_encoding, $to_encoding, $str)
 {
     /*if ($from_encoding != CPAGE_UTF7_Imap && ConvertUtils::IsLatin($str))
     		{
     			return ConvertUtils::IsUtf7($str) ? str_replace('&', '&-', $str) : $str;
     		}/**/
     if ($from_encoding == CPAGE_UTF7_Imap || $to_encoding == CPAGE_UTF7_Imap) {
         $i18str = new I18nString($str, $from_encoding);
         return $i18str->GetText($to_encoding);
     }
     if (strtolower($from_encoding) == 'ascii') {
         $from_encoding = 'iso-8859-1';
     }
     if (strtolower($from_encoding) == 'ks_c_5601-1987') {
         $from_encoding = 'EUC-KR';
     }
     $iconv_encodings_array = array('ascii', 'iso-8859-1', 'iso-8859-2', 'iso-8859-3', 'iso-8859-4', 'iso-8859-5', 'iso-8859-6', 'iso-8859-7', 'iso-8859-8', 'iso-8859-9', 'iso-8859-10', 'iso-8859-11', 'iso-8859-12', 'iso-8859-13', 'iso-8859-14', 'iso-8859-15', 'iso-8859-16', 'koi8-r', 'koi8-u', 'koi8-ru', 'cp1250', 'cp1251', 'cp1252', 'cp1253', 'cp1254', 'cp1257', 'cp949', 'cp1133', 'cp850', 'cp866', 'cp1255', 'cp1256', 'cp862', 'cp874', 'cp932', 'cp950', 'cp1258', 'windows-1250', 'windows-1251', 'windows-1252', 'windows-1253', 'windows-1254', 'windows-1255', 'windows-1256', 'windows-1257', 'windows-1258', 'windows-874', 'macroman', 'maccentraleurope', 'maciceland', 'maccroatian', 'macromania', 'maccyrillic', 'macukraine', 'macgreek', 'macturkish', 'macintosh', 'machebrew', 'macarabic', 'euc-jp', 'shift_jis', 'iso-2022-jp', 'iso-2022-jp-2', 'iso-2022-jp-1', 'euc-cn', 'gb2312', 'hz', 'gbk', 'gb18030', 'euc-tw', 'big5', 'big5-hkscs', 'iso-2022-cn', 'iso-2022-cn-ext', 'euc-kr', 'iso-2022-kr', 'johab', 'armscii-8', 'georgian-academy', 'georgian-ps', 'koi8-t', 'tis-620', 'macthai', 'mulelao-1', 'viscii', 'tcvn', 'hp-roman8', 'nextstep', 'utf-8', 'ucs-2', 'ucs-2be', 'ucs-2le', 'ucs-4', 'ucs-4be', 'ucs-4le', 'utf-16', 'utf-16be', 'utf-16le', 'utf-32', 'utf-32be', 'utf-32le', 'utf-7', 'c99', 'java', 'ucs-2-internal', 'ucs-4-internal');
     if (in_array(strtolower($from_encoding), $iconv_encodings_array)) {
         $result = @iconv($from_encoding, $to_encoding . '//IGNORE', $str);
         return $result !== false ? $result : $str;
     }
     return $str;
 }