JavaScript实现页面背景色动态切换源码

<!DOCTYPE html> 
<html lang="en"> 
<head> 
  <meta charset="UTF-8"> 
  <title>Document</title> 
  <style> 
    .big_box{ 
      width: 500px; 
      height: 500px; 
      border: 1px solid black; 
    } 
    .big_box input{ 
      margin-left: 60px; 
    } 
  </style> 
  <script> 
    function Change_red(){ 
      var Red=document.getElementById("change_style"); 
      Red.style.backgroundColor="red"; 
    } 
    function Change_blue(){ 
      var Blue=document.getElementById("change_style"); 
      Blue.style.backgroundColor="blue"; 
    } 
    function Change_green(){ 
      var Green=document.getElementById("change_style"); 
      Green.style.backgroundColor="green"; 
    } 
  </script> 
</head> 
<body> 
  <div class="big_box" id="change_style"> 
    <input type="button" value="变为红色" onclick="Change_red()"> 
    <input type="button" value="变为蓝色" onclick="Change_blue()"> 
    <input type="button" value="变为绿色" onclick="Change_green()"> 
  </div> 
</body> 
</html>