what is this? (javascript function for background)

[El-Cherubin]

Hello,

I see this in the default template :

Code:

<script type="text/javascript"><!--
        try {
            document.execCommand("BackgroundImageCache", false, true);
        } catch(err) {}
        /* IE6 flicker hack from http://dean.edwards.name/my/flicker.html */
    --></script>

What is its utility? It's to do what?

Thanks for explanation to a newbie