js截取字符串

function cutstr(str, len,bPoint) ...{
        var temp;
        var icount = 0;
        var patrn = /[^\x00-\xff]/;
        var strre = "";
        var iaddcount=0;
        for (var i = 0; i < str.length; i++) ...{
            if (icount < len - 1) ...{
                temp = str.substr(i, 1);
                if (patrn.exec(temp) == null) ...{
                    icount = icount + 1;
                } else ...{
                    icount = icount + 2;
                }
                strre += temp;
                iaddcount++;
            } else ...{
                break;
            }
        }
        if(iaddcount<str.length && bPoint)
        ...{
           strre=strre + "...";
        }
        return strre;
    }