function highlightTab(whichTab){
    if (whichTab==1){
        document.getElementById('highlightTab1').src="/images/display/highlightTabs/announcements.gif";
        document.getElementById('highlightTab2').src="/images/display/highlightTabs/specialfeatures-off.gif";
        document.getElementById('tabSet1').style.display="block";
        document.getElementById('tabSet2').style.display="none";
    }
    else {
        document.getElementById('highlightTab1').src="/images/display/highlightTabs/announcements-off.gif";
        document.getElementById('highlightTab2').src="/images/display/highlightTabs/specialfeatures.gif";
        document.getElementById('tabSet1').style.display="none";
        document.getElementById('tabSet2').style.display="block";
    }
}