addEvent(window, 'load', extLinks);

/**
 * Make all external links (<a href="#" rel="external"></a>) pop up
 * in a new window
 */
function extLinks() {
	if (!document.getElementById || !document.createElement)
		return false;

	var link = null;

	for (var i = 0; (link = document.getElementsByTagName('a')[i]); i++) {
		if (link.rel == 'external')
			link.onclick = function() { window.open(this.href); return false; };
	}
}

/**
 * Toggle visibility for boxes
 */
function showBox(boxid) {
	if (!document.getElementById || !document.createElement || !document.getElementById(boxid))
		return false;

	document.getElementById(boxid).style.display = 'block';
}

/**
 * Toggle visibility for boxes
 */
function hideBox(boxid) {
	if (!document.getElementById || !document.createElement || !document.getElementById(boxid))
		return false;

	document.getElementById(boxid).style.display = 'none';
}

/**
 * addEvent
 */
function addEvent(obj, evType, fn) {
	if (obj.addEventListener) {
		obj.addEventListener(evType, fn, true);
		return true;
	} else if (obj.attachEvent) {
		var r = obj.attachEvent("on"+evType, fn);
		return r;
	} else {
		return false;
	}
}

/**
 * Dynamically add a class to an element
 */
function addClass(element, classAdd) {
	element.className += element.className ? ' ' + classAdd : classAdd;
}

/**
 * Dynamically remove a class to an element
 */
function removeClass(element, className) {
	var replace = element.className.match(' ' + className) ? ' ' + className : className;
	element.className = element.className.replace(replace, '');
}

var whichLink = 0;

/* Toggle a box's display on/off */
function toggleBox(id, labelBox) {
	if (!document.getElementById || !document.createElement)
		return false;

	if (whichLink == 0) {
		whichLink = 1;
	} else {
		whichLink = 0;
	}

	if (whichLink == 1){
		document.getElementById(id).style.display = 'block';
		labelBox.innerHTML = '<a href="#" onclick="toggleBox(\'' + id + '\', this.parentNode); return false;">Hide transcript</a>';
	} else {
		document.getElementById(id).style.display = 'none';
		labelBox.innerHTML = '<a href="#" onclick="toggleBox(\'' + id + '\', this.parentNode); return false;">Show transcript</a>';
	}
}