Summary of common functions in Javascript

/*判断浏览器版本*/ 
var w3c=(document.getElementById)? true: false; 
var agt=navigator.userAgent.toLowerCase(); 
var ie = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1) && (agt.indexOf("omniweb") == -1)); 
var ie5=(w3c && ie)? true : false; 
var ns6=(w3c && (navigator.appName=="Netscape"))? true: false; 
var op8=(navigator.userAgent.toLowerCase().indexOf("opera")==-1)? false:true; 
function ExChgCls(o,a,b){//切换对象的className 
o.className=o.className==a?b:a; 
} 
function ExChgHtml(o,a,b){//切换对象的innerHTML 
o.innerHTML=o.innerHTML==a?b:a; 
} 
function Oh(o,s){ //输出字符串给某个对象 
Ob(o).innerHTML=s; 
} 
function SetSrc(o,s){//改变img、iframe等对象的src值 
Ob(o).src=s; 
} 
function Ob(o){//取得一个对象 
return document.getElementById(o)?document.getElementById(o):o; 
} 
function IsSubStr(p,s){//判断是否为子字符串 
return (p.indexOf(s)>-1); 
} 
function Hd(o){//隐藏某个对象 
Ob(o).style.display="none"; 
} 
function Sw(o){//显示某个对象 
Ob(o).style.display="block"; 
} 
function Sw2(o){//显示某个对象 
Ob(o).style.display=""; 
} 
function Sf(o,s,b){ 
//该函数用于多按钮共用同一表单,其中：o为表单的ID b为隐藏的input的ID(其value供后如判断用户提交动作类型) s为用户提交动作类型 
Ob(b).value=s; 
Ob(o).submit(); 
}
/*XmlHttp*/ 
function Gp(url,o){ //GetHttpPage 
var o=Ob(o); 
var PageRequest = false; 
IsLoading(o); 
if (window.XMLHttpRequest) {// if Mozilla, Safari etc 
PageRequest = new XMLHttpRequest(); 
} 
else if (window.ActiveXObject){ // if IE 
try { 
PageRequest = new ActiveXObject("Msxml2.XMLHTTP"); 
} 
catch (e){ 
try{ 
PageRequest = new ActiveXObject("Microsoft.XMLHTTP"); 
} 
catch (e){;} 
} 
} 
else {return false ;} 
PageRequest.onreadystatechange=function(){ 
if (PageRequest.readyState == 4) { 
Lp(PageRequest,o); 
} 
} 
PageRequest.open('GET', url, true); 
PageRequest.send(null); 
} 
function Lp(PageRequest,o){ //LoadPage 
if (PageRequest.readyState == 4 && (PageRequest.status==200 || window.location.href.indexOf("http")==-1)) 
Ob(o).innerHTML=PageRequest.responseText; 
//Hd("OpMsg"); 
} 
function IsLoading(o){ 
o.innerHTML="数据加载中，请稍候......"; 
//Sw2("OpMsg"); 
}