截取字符串显示指定长度,超过部分用省略

function getInterceptedStr(sSource, iLen) {    if (sSource.replace(/[^\x00-\xff]/g, "xx").length <= iLen) {        return sSource;    }    var str = "";    var l = 0;    var schar;    for (var i = 0; schar = sSource.charAt(i); i++) {        str += schar;        l += (schar.match(/[^\x00-\xff]/) != null ? 2: 1);        if (l >= iLen) {            str += "....";            break;        }    }    return str;}