var activeTab=false;

function basename(path) {

    return path.replace(/\\/g,'/').replace( /.*\//, '' );

}

function rollOn(tab){
    var tabOb = document.getElementById(tab);
       tabOb.src='images/'+tab+'Hover.gif';
}

function rollOff(tab){
    var tabOb = document.getElementById(tab);
    //document.write(basename(tabOb.src));

    if(activeTab==tab){
       tabOb.src='images/'+tab+'Hover.gif';
    }
    else
        tabOb.src='images/'+tab+'.gif';

}
function changeState(tab){
    var tabOb = document.getElementById(tab);
    tabOb.src='images/'+tab+'Hover.gif';
    activeTab=tab;
}