最近使用position属性进行界面布局，在以后的开发中将要经常使用，便于以后使用方便特别把样式写在这里：
<!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>all a</title>
</head>
<body>
<div>
<div>
<a href="www.baidu.com">baidu</a>
<a href="www.baidu.com">baidu</a>
<a href="www.baidu.com">baidu</a>
<a href="www.baidu.com">baidu</a>
<a href="www.baidu.com">baidu</a>
</div>
<div>
aaaaaaaaaaaaaaaa
</div>
</div>
<div>
<div>
content
</div>
<div>
aaaaaaaaaaaaaaaa
</div>
</div>
<script language="javascript">
function addTarget(){
var allAitem = document.getElementsByTagName("a");
var allAnum = allAitem.length;
for(var i=0; i<allAnum; i++){
allAitem[i].setAttribute("target","_blank");
}
}
addTarget();
</script>
</body>
</html>