How to set background size (height & width)?

Question

I'm very new to JavaScript.

My code so far:

$("#Stage").css(
  "background-image",
  "url(BG.jpg)",
  "background-attachment", 
  "fixed"
);

What I want to do is have the background image at a set size so lets say: width: 100% and height: 100%.

Solution

You want to use background-size: 100%. Ensure that its browser support is compatible with your supported platforms.

$("#Stage").css({ 
     "background-image": "url(BG.jpg)", 
     "background-attachment": "fixed",
     "background-size": "100%"
});