Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trial![](https://ecs-static.teamtreehouse.com/assets/views/marketing/shared/community-banner-white-47072046c51352fe6a69f5e691ff5700b28bb11d45197d7bdf066d9ea3f72d0c.webp)
![Rashad Nelson](https://secure.gravatar.com/avatar/8be9388e561fa882e18333de37fa272d?s=96&d=https%3A%2F%2Fecs-static.teamtreehouse.com%2Fassets%2Fcontent%2Fdefault_avatar-445fbbabfc8dc9188fb5967fe43322ee0c3e0dd1e10f378bf8343784af5a13eb.webp&r=pg)
Rashad Nelson
6,532 PointsPlease review my code
I get it for the most part. we are pulling the warning div into the variable warning. We create the listener and add function. Is the code im running in the call back function wrong. If i wanted to use the css selector of ID would #warning{background-color: red} work as well or since we are working with the DOM better to user the style.element. option.
var warning = document.getElementById("warning");
var button = document.getElementById('makeItRed');
button.addEventListener('click', (warning) => {
warning.style.backgroundColor = 'red';
});
<!DOCTYPE html>
<html>
<head>
<title>Adding an Event Listener</title>
</head>
<link rel="stylesheet" href="style.css" />
<body>
<div id="warning">
Warning: My background should be red!
</div>
<button id="makeItRed">Make It Red!</button>
<script src="app.js"></script>
</body>
</html>
1 Answer
![Steven Parker](https://uploads.teamtreehouse.com/production/profile-photos/969492/micro_tool_chess_set_2.jpg)
Steven Parker
230,688 PointsBy naming the parameter of your event handler "warning", it "shadows" (prevents access to) the global "warning" variable you defined in task 2.
Give the parameter another name ("event" or "e" are both commonly used) and the handler will work as expected.