# getElementById("bodyId").style.background:url ? **URL:** \ **Category:** programming\ **Created:** [August 28, 2019, 11:23pm UTC](https://forum.kirupa.com/t/getelementbyid-bodyid-style-background-url/640342 "2019-08-28T23:23:03Z")\ **Posts on this page:** 5\ **Page:** 1

**Author:** ![vmars316](https://avatars.discourse-cdn.com/v4/letter/v/bcef8e/32.png) [@vmars316](https://forum.kirupa.com/u/vmars316)\ **Post date:** [August 28, 2019, 11:23pm UTC](https://forum.kirupa.com/t/getelementbyid-bodyid-style-background-url/640342/1 "2019-08-28T23:23:03Z")

Hello & Thanks: I need help modifying css attribute . I want to change the: #bodyId { font-family: Comic Sans MS; background-image: url(background-image-01.jpg) ; background-repeat: no-repeat; background-size: cover; } Code runs with no errors , but no results . Here is my code: ```auto
``` Thanks for your help ! ---

**Author:** ![kirupa](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/kirupa/32/11616_2.png) [@kirupa](https://forum.kirupa.com/u/kirupa)\ **Post date:** [August 29, 2019, 7:09am UTC](https://forum.kirupa.com/t/getelementbyid-bodyid-style-background-url/640342/2 "2019-08-29T07:09:14Z")

The way you set the `backgroundImage` via JavaScript is by doing something similar to the following: ```auto var rocketElement = document.querySelector(".rocket"); rocketElement.style.backgroundImage = `url(https://www.kirupa.com/images/rocket.svg)`; ``` Your property is the CSS property name (both `backgroundImage` or `background-image` like you have will work). You shouldn’t mix any part of the value as a part of specifying the property. 🙂 ---

**Author:** ![vmars316](https://avatars.discourse-cdn.com/v4/letter/v/bcef8e/32.png) [@vmars316](https://forum.kirupa.com/u/vmars316)\ **Post date:** [August 29, 2019, 4:27pm UTC](https://forum.kirupa.com/t/getelementbyid-bodyid-style-background-url/640342/3 "2019-08-29T16:27:22Z")

Ugh ! Still have probs , see code: If I use this combination: background-image: url(background-image-01.jpg) ; // css if (imageCount == 1) {targetBg.style.background-image = “url(background-image-02.jpg)” ; } // js I get this error: Uncaught ReferenceError: Invalid left-hand side in assignment If I use this combination: backgroundImage: url(background-image-01.jpg) ; // css if (imageCount == 1) {targetBg.style.backgroundImage = “url(background-image-02.jpg)” ; } // js I get this error: Uncaught TypeError: Cannot read property ‘style’ of null at changeImage AND no image is displayed . ```auto
``` Thanks ---

**Author:** ![vmars316](https://avatars.discourse-cdn.com/v4/letter/v/bcef8e/32.png) [@vmars316](https://forum.kirupa.com/u/vmars316)\ **Post date:** [August 29, 2019, 5:54pm UTC](https://forum.kirupa.com/t/getelementbyid-bodyid-style-background-url/640342/4 "2019-08-29T17:54:10Z")

Happy t say , I found my error: Had this: var targetBg = document.getElementById(“body”); Should of had this: var targetBg = document.getElementById(“bodyId”); Thanks ---

**Author:** ![kirupa](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/kirupa/32/11616_2.png) [@kirupa](https://forum.kirupa.com/u/kirupa)\ **Post date:** [August 29, 2019, 6:35pm UTC](https://forum.kirupa.com/t/getelementbyid-bodyid-style-background-url/640342/5 "2019-08-29T18:35:25Z")

Haha nice work! This one is is my favorite error: ``` Uncaught TypeError: Cannot read property ‘style’ of null ``` It almost always means that there is some typo I made in my `getDocumentBy*` or `querySelector` call 😛