int n = sitename.length - 2;
        int j, k;
        string save;
        for (k = n - 1; k >= 0; k--)
        {
            j = k + 1;
            save = sitename[k];
            sitename[n + 1] = save;
            while ((save,sitename[j]) > 0)
            {
                sitename[j - 1] = sitename[j];
                j++;
            }

            sitename[j - 1] = save;
        }  
 sitename[n + 1] = save;这样赋值的结果是多少呢?

运行下不就知道了么...

save = sitename[k];
sitename[n + 1] = save;

sitename[n + 1] = sitename[k];

你那sitename是不是字符串啊
但是你又怎么给它赋值呢？
没搞懂