HTML DOM ( 文档对象模型 )
HTML DOM 树

1)通过id查找html元素:var x = document.getElementById( " id " );
var y = x.getElementsByTagName( " p " );
2)改变<img> 元素的src属性,document.getElementById( " Image " ). src = " xxx.jpg " ;
3)javascript对html的事件的处理:onclick = " js 方法" ;onmouseover , onmouseout事件
4)创建html Elment:var p = document.createElement( " p " );
var node = document.createTextNode( " xxx " );
p.appendchild( node );