var lastAboutTab;
        
function showabout()
{
    var div1 = document.getElementById('aboutus');
    var table1 = document.getElementById('abouttable');    
    
    if(div1.style.visibility == 'hidden')
    {
        div1.style.visibility = 'visible';
        div1.style.position = 'static';
        
        if(lastAboutTab == null)
            lastAboutTab = document.getElementById('about1');
        
        lastAboutTab.style.position = 'static';
        lastAboutTab.style.visibility = 'visible';
    }
    else
    {
        if(lastAboutTab)
        {
            lastAboutTab.style.position = 'absolute';
            lastAboutTab.style.visibility = 'hidden';
        }
        
        div1.style.visibility = 'hidden';
        div1.style.position = 'absolute';
    }
    
    table1.style.visibility = div1.style.visibility;
    table1.style.position = div1.style.position;
}

function showabouttab(divname)
{
    div1 = document.getElementById(divname);
    if(lastAboutTab == div1) return;
    
    div1.style.position = 'static';
    div1.style.visibility = 'visible';
    
    if(lastAboutTab)
    {
        lastAboutTab.style.position = 'absolute';
        lastAboutTab.style.visibility = 'hidden';
    }
    
    lastAboutTab = div1;
}