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<!DOCTYPE html> <html> <head> <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script> </head> <body> <h1>change background color by using jquery</h1> <button id="btn-bg">change bg color</button> <p>click on above button</p> <script> $(document).ready(function(){ $("#btn-bg").click(function(){ $("body").css("background-color","red"); }); }); </script> </body> </html>