Edit this line
<span id="fxma" class="instructiontext">FILTER (to insert the id=) and replace this function
function resizeIframe(frameid) {
var currentfr = document.getElementById(frameid)
var cAs = document.getElementById('fxma').getElementsByTagName('a')
for (j = cAs.length, i = 0; i < j; i++) {
cAs[i].style.backgroundColor = 'white'
}
var a;
switch (window.frames['fxm'].document.URL) {
case 'http://www.rjt-online.com/photos_latest.php':
a = 'LATEST';
cAs[0].style.backgroundColor = 'silver'
break
case 'http://www.rjt-online.com/photos_live.php':
a = 'LIVE';
cAs[1].style.backgroundColor = 'silver'
break
case 'http://www.rjt-online.com/photos_promo.php':
a = 'PROMO';
cAs[2].style.backgroundColor = 'silver'
break
case 'http://www.rjt-online.com/photos_other.php':
a = 'OTHER';
cAs[3].style.backgroundColor = 'silver'
break
case 'http://www.rjt-online.com/photos_view_all.php':
a = 'ALL';
cAs[4].style.backgroundColor = 'silver'
break
}
document.getElementById('phototitle').innerHTML = a + ' PHOTOS //';
}
in its entirety.
Adjust the colors to taste. Obviously different highlighting styles are possible.