_specwin(func, ser, fwin, len, winc, dc, sym, dwin)
{
        local dataser;

        dataser = _winfunform(ser, fwin, winc, dc, sym);

        if (strcmp(len, "-1") == 0)
        {
                eval(sprintf("setwf(%s, '%s(%s)')", dwin, func, dataser));
        }
        else if (strcmp(len, "-2") == 0)
        {
                eval(sprintf("setwf(%s, '%s(%s, bestpow2(%s))')", dwin, func, dataser, ser));
        }
        else
        {
                eval(sprintf("setwf(%s, '%s(%s, %s)')", dwin, func, dataser, len));
        }
}