<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
</head>
<body>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
var s = "";
s += "\r\n屏幕分辨率的宽："+ window.screen.width;
alert(s);
}
</script>
</body>
</html>