currentShownDiv = "";

function klapp(id)
{
currentShownObj = document.getElementById(currentShownDiv);

if (currentShownObj != null)
currentShownObj.style.display='none';

if (id == currentShownDiv)
{
currentShownDiv = "";
return;
}

currentShownDiv = id;

objToShow = document.getElementById(id);

if (objToShow.style.display == 'none')
{objToShow.style.display='block';}
else
{objToShow.style.display='none';}
}