Question

I hope I ask this correctly. What I want to do is set a background to the body of my website page which fills the users screen. So the image stretches if the screen is big and when they reduce the browser the background image reduces with it?

#homebdy
{
   background-image:url('../images/bghome.jpg');
}

Answer 1

This will do it for you:

#homebdy{
  background-image:url('../images/bghome.jpg');
  height: 100%;
  position: absolute;
  top: 0;
}

Next step would be to center the image depending on viewport size. There for I would recommend the use of jQuery. For example if you use pictures with a ratio of 4:3, then do this:

var indent = (($(window).width() - (($(this).height())/3)*4) / 2);
$('#homebdy').offset({left: indent});

You can see a live example on a website I am building currently