21、原生JavaScript中有insertBefore方法,可惜却没有insertAfter方法?用如下函数实现

function insertAfter(newChild,refChild){ 
        var parElem=refChild.parentNode; 
        if(parElem.lastChild==refChild){ 
                refChild.appendChild(newChild); 
        }else{ 
                parElem.insertBefore(newChild,refChild.nextSibling); 
        } 
} 

22、原生JavaScript中兼容浏览器绑定元素事件

function addEventSamp(obj,evt,fn){ 
        if (obj.addEventListener) { 
                obj.addEventListener(evt, fn, false); 
        }else if(obj.attachEvent){ 
                obj.attachEvent('on'+evt,fn); 
        } 
}

23、原生JavaScript光标停在文字的后面，文本框获得焦点时调用

function focusLast(){ 
        var e = event.srcElement; 
        var r =e.createTextRange(); 
        r.moveStart('character',e.value.length); 
        r.collapse(true); 
        r.select(); 
}

24、原生JavaScript检验URL链接是否有效

function getUrlState(URL){ 
        var xmlhttp = new ActiveXObject("microsoft.xmlhttp"); 
        xmlhttp.Open("GET",URL, false);  
        try{  
                xmlhttp.Send(); 
        }catch(e){
        }finally{ 
                var result = xmlhttp.responseText; 
                if(result){ 
                        if(xmlhttp.Status==200){ 
                                return(true); 
                        }else{ 
                                return(false); 
                        } 
                }else{ 
                        return(false); 
                } 
        } 
}

25、原生JavaScript格式化CSS样式代码

function formatCss(s){//格式化代码
        s = s.replace(/\s*([\{\}\:\;\,])\s*/g, "$1");
        s = s.replace(/;\s*;/g, ";"); //清除连续分号
        s = s.replace(/\,[\s\.\#\d]*{/g, "{");
        s = s.replace(/([^\s])\{([^\s])/g, "$1 {\n\t$2");
        s = s.replace(/([^\s])\}([^\n]*)/g, "$1\n}\n$2");
        s = s.replace(/([^\s]);([^\s\}])/g, "$1;\n\t$2");
        return s;
}

26、原生JavaScript压缩CSS样式代码

function yasuoCss (s) {//压缩代码
        s = s.replace(/\/\*(.|\n)*?\*\//g, ""); //删除注释
        s = s.replace(/\s*([\{\}\:\;\,])\s*/g, "$1");
        s = s.replace(/\,[\s\.\#\d]*\{/g, "{"); //容错处理
        s = s.replace(/;\s*;/g, ";"); //清除连续分号
        s = s.match(/^\s*(\S+(\s+\S+)*)\s*$/); //去掉首尾空白
        return (s == null) ? "" : s[1];
}

27、原生JavaScript获取当前路径

var currentPageUrl = "";
if (typeof this.href === "undefined") {
    currentPageUrl = document.location.toString().toLowerCase();
}
else {
    currentPageUrl = this.href.toString().toLowerCase();
}

28、原生JavaScriptIP转成整型

function _ip2int(ip){
    var num = 0;
    ip = ip.split(".");
    num = Number(ip[0]) * 256 * 256 * 256 + Number(ip[1]) * 256 * 256 + Number(ip[2]) * 256 + Number(ip[3]);
    num = num >>> 0;
    return num;
}

29、原生JavaScript整型解析为IP地址

function _int2iP(num){
    var str;
    var tt = new Array();
    tt[0] = (num >>> 24) >>> 0;
    tt[1] = ((num << 8) >>> 24) >>> 0;
    tt[2] = (num << 16) >>> 24;
    tt[3] = (num << 24) >>> 24;
    str = String(tt[0]) + "." + String(tt[1]) + "." + String(tt[2]) + "." + String(tt[3]);
    return str;
}

30、原生JavaScript实现checkbox全选与全不选

function checkAll() {
        var selectall = document.getElementById("selectall");
        var allbox = document.getElementsByName("allbox");
        if (selectall.checked) {
                for (var i = 0; i < allbox