function addLoadEvent (func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	} else {
		window.onload = function () {
			oldonload();
			func();
		}
	}
}

function popOver() {
	var popOverDiv = document.getElementById("popover");
	var pList = popOverDiv.getElementsByTagName("p");
	for (var i = 0; i < pList.length; i++) {
		var thisP = pList[i];
		if (thisP.className == "close") {
			var closeLink = thisP.firstChild;
			closeLink.onclick = function() {
				var popOverDiv = document.getElementById("popover");
				popOverDiv.style.display = "none";
			}
		}
	}
}

addLoadEvent(popOver);