function hideall()
{
hiderollcontact();
hiderollphotos();
hiderollexpeditions();
hiderollblog();
hiderollabout();
hiderollwritings();
}

function showrollblog()
{
  var myDiv = document.getElementById('blogroll');
  myDiv.style.display = "block";
}

function hiderollblog()
{
  var myDiv = document.getElementById('blogroll');
  myDiv.style.display = "none";
}



function showrollabout()
{
  var myDiv = document.getElementById('aboutroll');
  myDiv.style.display = "block";
}

function hiderollabout()
{
  var myDiv = document.getElementById('aboutroll');
  myDiv.style.display = "none";
}



function showrollphotos()
{
  var myDiv = document.getElementById('photosroll');
  myDiv.style.display = "block";
}

function hiderollphotos()
{
  var myDiv = document.getElementById('photosroll');
  myDiv.style.display = "none";
}



function showrollwritings()
{
  var myDiv = document.getElementById('writingsroll');
  myDiv.style.display = "block";
}

function hiderollwritings()
{
  var myDiv = document.getElementById('writingsroll');
  myDiv.style.display = "none";
}



function showrollexpeditions()
{
  var myDiv = document.getElementById('expeditionsroll');
  myDiv.style.display = "block";
}

function hiderollexpeditions()
{
  var myDiv = document.getElementById('expeditionsroll');
  myDiv.style.display = "none";
}




function showrollcontact()
{
  var myDiv = document.getElementById('contactroll');
  myDiv.style.display = "block";
}

function hiderollcontact()
{
  var myDiv = document.getElementById('contactroll');
  myDiv.style.display = "none";
}



var rollOverArr=new Array();
function setrollover(OverImgSrc,pageImageName)
{
if (! document.images)return;
if (pageImageName == null)
    pageImageName = document.images[document.images.length-1].name;
rollOverArr[pageImageName]=new Object;
rollOverArr[pageImageName].overImg = new Image;
rollOverArr[pageImageName].overImg.src=OverImgSrc;
}

function rollover(pageImageName)
{
if (! document.images)return;
if (! rollOverArr[pageImageName])return;
if (! rollOverArr[pageImageName].outImg)
    {
    rollOverArr[pageImageName].outImg = new Image;
    rollOverArr[pageImageName].outImg.src = document.images[pageImageName].src;
    }
document.images[pageImageName].src=rollOverArr[pageImageName].overImg.src;
}

function rollout(pageImageName)
{
if (! document.images)return;
if (! rollOverArr[pageImageName])return;
document.images[pageImageName].src=rollOverArr[pageImageName].outImg.src;
}