javascript 方法一些使用方法

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title>无标题文档</title> 
<script language="javascript" type="text/javascript" > 
function chens(a,b,c,d) 
{ 
this.a=a==null?alert("a"):"chen"; 
b==null?alert("b"):""; 
c==null?alert("c"):""; 
document.write(this.a); 
this.d==null?alert("d"):""; 
} 
</script> 
</head> 
<body> 
<input type="button" id="btnan" value="dkdk"/> 
<input type="button" onclick="location.replace('//www.gxlcms.com');" value="dkskk"/> 
<script> 
var newopen = function(i) 
{ 
return function() 
{ 
location.replace("//www.gxlcms.com"); 
} 
} 
if (document.getElementById("btnan").attachEvent) 
{ 
document.getElementById("btnan").attachEvent("onclick",newopen("popo")); 
} 
else 
{ 
document.getElementById("btnan").addEventListener("click",newopen("tyty"),false); 
} 
</script> 
</body> 
</html>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]