代码示例:(标识:jsref_window_blur)
<!DOCTYPE html>
<html>
<head>
<script>
var myWindow;
function openWin() {
  myWindow = window.open("", "", "width=400, height=200");
  myWindow.blur();
}
function blurWin() {
  myWindow.blur();
}
function focusWin() {
  myWindow.focus();
}
</script>
</head>
<body>

<input type="button" value="打开新窗口" onclick="openWin()">
<input type="button" value="失焦新窗口" onclick="blurWin()">
<input type="button" value="聚焦新窗口" onclick="focusWin()">

</body>
</html>
运行结果: