I'm trying to use this image as the background for a visualforce page without repeats. This is the code I have so far, but it's not working. Do I have to save the image in Salesforce first. If so, could you walk me through that? Thanks.
<body style="background-image: url('{http://www.jpl.nasa.gov/spaceimages/images/mediumsize/PIA17011_ip.jpg}')no-repeat top fixed;">
On
The image you want to use for body tag is pointing to outside salesforce, hence it might be blocked.
Solution could be:
Either download the image in static resource and use tag as mentioned by Daniel, which is always a good practice.
Add the URL in the remote site setting from setup.
Visualforce will provide the body tag for you. Instead you should use a
styleelement or<apex:stylesheet/>to define the body style.See Using Custom Styles