var currentItem="item1";
function switchItem(which) {
document.getElementById(currentItem).style.display='none';
document.getElementById(which).style.display='block';
currentItem=which;
}

function openWin(url,winname) {
  myWin= window.open(url, winname,    "width=650,height=450,status=yes,locationbar=yes,toolbar=yes,menubar=yes,resizable=yes,scrollbars=yes");
}

function showItem(item) {
if (document.getElementById(item).style.display=='none')
document.getElementById(item).style.display='block';
else document.getElementById(item).style.display='none';
}