CSS Opacity problem

Hi guys,

I have a style sheet where when the user hovers over a <td>, it uses the style below. What I want is for a semi-transparent white background to display(overlaying the background image of the table). The code below does this. The problem is, it also makes the text in the <td> and the borders more transparent.

Is there any way of just making the background of the cells transparent, and not the content aswell???

Any help would be much appreciated.

td.selected {
background-color: #ffffff;
filter: alpha(opacity = 50);
border-top: 1px solid #330033;
border-left: 1px solid #330033;
border-right: 1px solid #330033;
color: #000000;
font-family: arial;
font-weight: bold;
font-size: 11px;
height: 20px;
cursor: hand;
}