<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script src="js/jquery.js"></script>
<script>
window.onload = function(){
document.getElementById('btnok').onclick=function(){
//id选择器
//$('#div3').html('aaaaaaa');
//class选择器
$('.div2').html('aaaaaaaaaaaaaa');
//多标签选择
$('h1,div').html('aaaaaaaaa');
}
}
</script>
</head>
<body>
<input type="button" id="btnok" value="OK" />
<hr>
<h1>111111</h1>
<hr>
<div>222222222</div>
<div class="div2">333333333</div>
<div id="div3">444444444</div>f
</body>
</html>