utf-8编码转换成gb2312

                                                           ((icode1  &  0x3f)  <<    6)    ¦  
                                                           (icode2  &  0x3f));  
                                   noffset  +=  3;  
                                   nremainingbytes  -=  3;  
                       }  
                       else                                                                                                //  4  or  more  bytes  --  unsupported  
                                   break;  
           }  

           if  (nremainingbytes  !=  0)  
           {  
                       //  bad  utf8  string.