js 鼠标移入移出事件

var oFlag = document.getElementById('flag');
var oDiv = document.getElementById('node');
//鼠标移入事件
oDiv.onmouseover = function() {
	oFlag.style.display = 'block';
}
//鼠标移出事件
oDiv.onmouseout = function() {
	oFlag.style.display = 'none';
}