js html 交互监听事件学习

<input type="button" value="Click Here" onclick="showMessage();" />
<script type="text/javascript">
function showMessage() {
alert('Clicked!');
}

<input id="btnClick" type="button" value="Click Here" />

<script type="text/javascript">
var btnClick = document.getElementById('btnClick');
btnClick.onclick = function showMessage() {
alert(this.id);
};
</script>

<input id="btnClick" type="button" value="Click Here" />

<script type="text/javascript">
var btnClick = document.getElementById('btnClick');
btnClick.addEventListener('mouseover', function() {
alert(this.id);
}, false);
btnClick.addEventListener('click', function() {
alert('Hello!');
}, false);
</script>

add与remove的参数必须一样
<input id="btnClick" type="button" value="Click Here" />

<script type="text/javascript">
var btnClick = document.getElementById('btnClick');
var handler=function() {
alert(this.id);
}
btnClick.addEventListener('click', handler, false);
btnClick.removeEventListener('click', handler, false);
</script>