here is another application about opacity, you can use it in divs in your web page. it will still without opacity until you cross over it in mouse. this is an example on how to use it. it works in firefox, opera and internet explorer, i hope you will like it.
add this to your CSS file
div.transOFF {width: 100%; background-color: silver;border:1px solid black; }
div.transON {width: 100%; background-color: silver;opacity:.50;filter: alpha(opacity=50); -moz-opacity: 0.5;border:1px solid black; }
div.trans25 {width: 100%; background-color: silver;opacity:.25;filter: alpha(opacity=25); -moz-opacity: 0.25;border:1px solid black; }
div.trans75 {width: 100%; background-color: silver;opacity:.75;filter: alpha(opacity=75); -moz-opacity: 0.75;border:1px solid black; }
add this to your body tag
<div class="transOFF" onmouseover="this.className='transON'" onmouseout="this.className='transOFF'"><p style="padding:5px;width:75%;">Hover here. The Filter Opacity works in Mozilla and IE. It also works in current versions of Opera.</p></div>
with a little bit of changes you can use it on images too. have fun.

















