It would be something like this:
a.subnav
{
Font-family: Verdana, Arial, Helvetica, sans-serif;
Font-size:11px;
Font-weight: normal;
Color: #0000FF;
Text-decoration: underline
}
a:visited.subnav
{
Font-family: Verdana, Arial, Helvetica, sans-serif;
Font-size: 11px;
Font-weight: normal;
Color: #0000FF;
Text-decoration: underline
}
a:hover.subnav
{
Font-family: Verdana, Arial, Helvetica, sans-serif;
Font-size: 11px;
Font-weight: normal;
Color: #FF0000;
Text-decoration: none
}
a:active.subnav
{
Font-family: Verdana, Arial, Helvetica, sans-serif;
Font-size: 11px;
Font-weight: normal;
Color: #0000FF;
Text-decoration: underline
}
To read more about Pseudo Classes & to test them:
http://www.w3schools.com/css/css_pseudo_classes.asp