var newWindow = null;

function openWindow(contentURL,windowName,windowWidth,windowHeight) {
	widthHeight = 'height=' + windowHeight + ',width=' + windowWidth;
	newWindow = window.open(contentURL,windowName,widthHeight);
	newWindow.focus();
}

function closeWindow() {
	if (newWindow != null)  {	
	 newWindow.close();
	 newWindow = null;
	}
}