Javascript and Browser background

Hello!

I am a novice javascripter, and I'm hoping someone out there may be able to assist me.

I have been inspired by Melissa Milloway's article to manipulate the browser backgrounds of a course I am creating. The issue is that most users will have ie8 and backgroundSize = "cover" is not supported. I am trying to find a workaround. Note, the code below works great in Chrome.

I "think" this option could be a workaround, but I am unsure how I would incorporate that code into storyline to make that work.

My current code:

if (document.body){document.body.background = "backgrounds2/RCC_Title_1900.png";
document.body.style.backgroundSize = "cover";
document.body.style.backgroundRepeat = "no-repeat";
}

Thank you for any assistance!