Разбирает:
<div id="block" style="background:url(clock.png),-moz-linear-gradient(bottom, #F7E82C 49%, #FFFF47 75%, #FFFF64 88%)"></div>
<script>
function st(prop){
return typeof prop == 'string' ? prop.match(/[^, ].+?(?=, url|, -moz-linear-gradient|$)/g) : prop.join(', ')
}
a=document.getElementById("block").style;
alert(st(a.background).join('\n\n'))
b=['url(no.png)'];
a.background=st(b);
alert(st(a.background).join('\n\n'))
</script>