window.onload = function(){
	var tabOne = document.getElementById('tabOne');
	var tabTwo = document.getElementById('tabTwo');
	var tabThree = document.getElementById('tabThree');
	var tabFour = document.getElementById('tabFour');
	var lastTab = document.getElementById('lastTab');
	var firstContent = document.getElementById('firstContent');
	var secondContent = document.getElementById('secondContent');
	var thirdContent = document.getElementById('thirdContent');
	var fourthContent = document.getElementById('fourthContent');
	var lastContent = document.getElementById('lastContent');
	var dropMenu = document.getElementById('dropMenu');
	if(tabOne){
		tabOne.onclick = function() {
	    firstContent.className = 'visible';
	    secondContent.className = 'invisible';
	    if (lastContent) {
	      lastContent.className = 'invisible';
			}
	    return false;
		}
	}
	if(tabTwo){
		tabTwo.onclick = function() {
	    firstContent.className = 'invisible';
	    secondContent.className = 'visible';
	    if (lastContent) {
	      lastContent.className = 'invisible';
			}
	    return false;
		}
	}
	if(lastTab){
		lastTab.onclick = function() {
	    firstContent.className = 'invisible';
	    secondContent.className = 'invisible';
	    lastContent.className = 'visible';
	    return false;
		}
	}
	if(tabThree){
		tabThree.onclick = function() {
	    thirdContent.className = 'visible';
	    fourthContent.className = 'invisible';
	    return false;
		}
	}
	if(tabFour){
		tabFour.onclick = function() {
	    thirdContent.className = 'invisible';
	    fourthContent.className = 'visible';
	    return false;
		}
	}
	var sfEls = document.getElementById("dropMenu").getElementsByTagName("LI");
	for (var i = 0; i < sfEls.length; i++) {
		sfEls[i].onmouseover = function() {
			showSubMenu(this);
		}
		sfEls[i].onmouseout  = function() {
			hideSubMenu(this);
		};
		if (sfEls[i].getElementsByTagName("UL").length > 0) {
			sfEls[i].className  = 'parent';
		}
	}
}
	function showSubMenu(menuItem)	{
		for ( i = 0; i < menuItem.childNodes.length; i++) {
			if (menuItem.childNodes[i].nodeName == 'UL') {
				menuItem.childNodes[i].style.display = 'block';
			}
		}
	}
	function hideSubMenu(menuItem) {
		var uls = menuItem.getElementsByTagName('ul');
		for ( i = 0; i < menuItem.childNodes.length; i++) {
			if (menuItem.childNodes[i].nodeName == 'UL') {
				menuItem.childNodes[i].style.display = 'none';
			}
		}
 }