setting CSS via JS

[sssweb]

I can't get the following portion of my javascript to set CSS opacity:

<script language="JavaScript">
...
var trans = 0.5;
elementid.opacity = trans;
</script>

This doesn't work either:

document.getElementById("elementid").opacity = trans;

[penders]

document.getElementById("elementid").style.opacity = trans;

You will also need to set the filter property if you intend to support IE8 and below...
document.getElementById("elementid").style.filter = 'alpha(opacity=' + trans*100 + ')';

[sssweb]

Thanks penders, that was it.

Yes, I have the IE8 code too; that came with the script and was working fine, but I couldn't convert it for other browsers. It's in a slightly different format:

elementid.filters( "alpha" ).opacity = 50;