Football league table

[blackeyes]

I have made a football league table and i would like when the mouse pointer is hovering over a certain team
That the background color would change to a lighter color. Something like this site:Football table

I have been using

<tr class="box"></tr>
and in an external style sheet i have got
tr.box:hover{
    background-color: #D0D0D0;
}

But it doesn't work. Could someone help me out here please.