var activeTabIdNumber = 1;


function tabOnClick(tabIdNumber) {
	activeTabIdNumber = tabIdNumber;
	
	for (var i = 1; i <= 4; i++) {
		if (document.getElementById("tab" + i) && document.getElementById("tabContent" + i)) {
			var tabElement = document.getElementById("tab" + i);
			var tabContentElement = document.getElementById("tabContent" + i);
			if (tabElement.innerHTML.length > 0 && tabContentElement.innerHTML.length > 0) {
				tabElement.style.backgroundImage = "url(media/images/navigation/tab-button-background.jpg)";
				tabContentElement.style.display = "none";
			}
		}
	}
	
	if (document.getElementById("tab" + tabIdNumber) && document.getElementById("tabContent" + tabIdNumber)) {
		var tabElement = document.getElementById("tab" + tabIdNumber);
		var tabContentElement = document.getElementById("tabContent" + tabIdNumber);
		if (tabElement.innerHTML.length > 0 && tabContentElement.innerHTML.length > 0) {
			tabElement.style.backgroundImage = "url(media/images/navigation/tab-button-background-active.jpg)";
			tabContentElement.style.display = "block";
		}
	}
}


function tabOnMouseOver(tabIdNumber) {
	if (document.getElementById("tab" + tabIdNumber)) {
		var tabElement = document.getElementById("tab" + tabIdNumber);
		if (tabIdNumber != activeTabIdNumber && tabElement.innerHTML.length > 0) {
			tabElement.style.backgroundImage = "url(media/images/navigation/tab-button-background-rollover.jpg)";
		}
	}
}


function tabOnMouseOut(tabIdNumber) {
	if (document.getElementById("tab" + tabIdNumber)) {
		var tabElement = document.getElementById("tab" + tabIdNumber);
		if (tabIdNumber != activeTabIdNumber && tabElement.innerHTML.length > 0) {
			tabElement.style.backgroundImage = "url(media/images/navigation/tab-button-background.jpg)";
		}
	}
}


function tabShowVideoThumbnail(parentElementId, videoObjectElementId, videoName) {
	var videoObject = document.getElementById(videoObjectElementId);
	var parentElementObject = document.getElementById(parentElementId);
	parentElementObject.style.display = "block";
	videoObject.style.display = "none";
}


function tabPlayVideo(videoParentElementId, thumbnailParentElementId, videoName) {
	var thumbnailParentElementObject = document.getElementById(thumbnailParentElementId);
	var videoParentElementObject = document.getElementById(videoParentElementId);
	thumbnailParentElementObject.style.display = "none";
	videoParentElementObject.style.display = "block";
}