I'd like some advice on this preloader.js i'm using.

PHP Code:
function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_pd.MM_p=new Array();
i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0i<a.lengthi++)
    if (
a[i].indexOf("#")!=0){ d.MM_p[j]=new Imaged.MM_p[j++].src=a[i];}}

MM_preloadImages('img/photostream/pic1.png''img/photostream/pic2.png''img/photostream/pic3.png' ); 
1. Should the function be called via a window.onload handler? if not, can it be called simply after the function is defined?

2. Is this too old school? is there something better to use!, or is there any reason this is not considered good practice?

huge thanks for any help on this!