想要实现鼠标移上接触时div模块变成粉色并改变大小，单击时变为绿色并改变大小，双击时变成蓝色并改变大小，移出接触时变回红色并回到原大小，
但不知道为什么单击没有效果，是因为有冲突吗？
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>常见事件类型</title>
<style>
.my_red{
width: 100px;
height: 100px;
background-color: red;
}
.my_green{
width: 200px;
height: 200px;
background-color: green;
}
.my_pink{
width: 150px;
height: 150px;
background-color: pink;
}
.my_blue{
width: 200px;
height: 100px;
background-color: blue;
}
</style>
<script>
window.onload = function () {
var oDiv = document.getElementById('div1');
oDiv.ondblclick = function () {
oDiv.className = 'my_green';
}
oDiv.onmouseover = function (){
oDiv.className = 'my_pink';
}
oDiv.onmouseout = function (){
oDiv.className = 'my_red';
}
oDiv.ondblclick = function (){
oDiv.className = 'my_blue';
}
}
</script>
</head>
<body>
<div id='div1' class='my_red'>我是div</div>
</body>
</html>
