var isSafari = /WebKit/i.test(navigator.userAgent);
var isOpera = (navigator.userAgent.toLowerCase().indexOf("opera") != -1);
var isGecko = (navigator.userAgent.toLowerCase().indexOf('gecko') != -1);
// Detect if the browser is isIE or not.
// If it is not isIE, we assume that the browser is NS.
var isIE = (navigator.appVersion.toLowerCase().indexOf('msie 6.0') != -1);
var isIE7 = (navigator.appVersion.toLowerCase().indexOf('msie 7.0') != -1);
var isFF2 = ((navigator.userAgent.toLowerCase().indexOf('gecko') != -1)&&(navigator.appVersion.toLowerCase().indexOf('5.0') != -1)&&(navigator.appVersion.toLowerCase().indexOf('webkit') == -1));
var isMac = (navigator.platform.toLowerCase().indexOf("mac") != -1);

document.getElementsByClassName = function(className, parentElement) {
  var children = (document.getElementById(parentElement) || document.body).getElementsByTagName('*');
  var elements = [], child, pattern = new RegExp("(^|\\s)" + className + "(\\s|$)");
  for (var i = 0, length = children.length; i < length; i++) {
    child = children[i];
    var elementClassName = child.className;
    if (elementClassName.length == 0) continue;
    if (elementClassName == className || elementClassName.match(pattern))
      elements.push(child);
  }
  return elements;
};

function setRollEvents() {
	if(isIE && !isIE7){
	} else {
	var elems2 = document.getElementsByClassName('RelatedVideosDiv');
	for (index in elems2) {
		elems2[index].onmouseover = handleMouseOverForImg;
		elems2[index].onmouseout = handleMouseOutForImg;		
	}
	var elemsTT = document.getElementsByClassName('ImgOverlayLarge');
	for (index in elemsTT) {
		elemsTT[index].style.visibility = 'visible';
		elemsTT[index].style.display = 'none';		
	}
	}
}


/**
 * On mouse over, display the the transparent play button.
 * 
 * @param {Object} event
 */
function handleMouseOverForImg(event) {
	if(isIE){
		this.getElementsByTagName('a')[0].getElementsByTagName('span')[0].style.display = "inline";
	}else{
		this.getElementsByTagName('a')[0].getElementsByTagName('img')[0].style.display = "inline";
	}	
	if(this.getElementsByTagName('div')[0]){
		this.getElementsByTagName('div')[0].style.display = "inline";
		//tooltipFollow(this.getElementsByTagName('div')[0].id);
	}
	//tooltipFollow(this.getElementsByTagName('div')[0].id);	
}


/**
 * On mouse out, display the transparent play button.
 * 
 * @param {Object} event
 */
function handleMouseOutForImg(event) {
	if(isIE){
		this.getElementsByTagName('a')[0].getElementsByTagName('span')[0].style.display = "none";
	}else{
		this.getElementsByTagName('a')[0].getElementsByTagName('img')[0].style.display = "none";
	}	
	if(this.getElementsByTagName('div')[0]){
		this.getElementsByTagName('div')[0].style.display = "none";
	}
}