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<!DOCTYPE html>
<html>
<body>
<p>本例使用 HTML DOM 将 "onselect" 事件分配给 input 元素。</p>
请选择一些文本:<input type="text" value="Hello world!" id="myText">
<p id="demo"></p>
<script>
document.getElementById("myText").onselect = function() {myFunction()};
function myFunction() {
  document.getElementById("demo").innerHTML = "You selected some text!";
}
</script>
</body>
</html>