How to Change a Background Dynamically in a Website. Using CSS and JavaScript, you can dynamically change the background on your website. You use the code to change the background each time a user ...

Click the "Background" tab and select "Graphic" from the "As" menu. Click the "Browse" button, select your background image and click the "Open" button. Select a graphic option in the "Type" section.

In Google Docs, you can add watermark, picture and solid color background to your page. Learn how to insert Background Images in Google Docs.

You need to remove the image that is currently in your background by clicking on the grey dot in the top left corner. This will remove the image and allow you to add a new one.