<!DOCTYPE html>charset="utf-8"W3Cschool教程(w3cschool.cn)点击按钮查看输入的对话框。onclick="myFunction()"点我id="demo"function myFunction(){var x;var person=prompt("请输入你的名字","Harry Potter");if (person!=null && person!=""){x="你好 " + person + "!今天感觉如何?";document.getElementById("demo").innerHTML=x;}}