# 欢迎
   function checksum(chars){
        var sum = 0; 
        for (var i=0; i<chars.length; i++){ 
        var c = chars.charCodeAt(i); 
        if ((c >= 0x0001 && c <= 0x007e) || (0xff60<=c && c<=0xff9f))
        { 
            sum++; 
        }
        else 
            {     
            sum+=2; 
           } 
         }     
           return sum/2;
        }