function changeDisplaySetup(){
	if (document.getElementById('t1'))
  {
  changeDisplay('t1', 'u1');
  }
else
  {
  changeDisplay('t2', 'u2');
  }

}

function changeDisplay(onid, ontab) {
	var onID = document.getElementById(onid);
	var onTab = document.getElementById(ontab);
	var tabHolder = document.getElementById('tab-container');
	var kids = tabHolder.childNodes; 
	for (i = 0; i < kids.length; ++i) {
	  if (kids[i].nodeType!=1) continue;
	  if (!(kids[i].className && (kids[i].className=='mss-tab' || kids[i].className=='mss-tab-on'))) continue;
		
    kids[i].className = 'mss-tab';

		key = kids[i].id.replace(/u/, 't');
		if (document.getElementById(key) != null) {
			document.getElementById(key).style.display = 'none';

		}

	}

	if (onID) onID.style.display = 'block';
	if (onTab) onTab.className= 'mss-tab-on';

}
changeDisplaySetup();