function startIntro() {
	var div = document.getElementById("main_container");
	if (div != null) {
		var state = div.className;
		var startState = state.indexOf("_on");
		if (startState != -1) {
			var test = state.substring(0, 3);
			var newClassName = state.substring(0, startState) + "_off";
			div.className = newClassName;

			toggleScreen(false);
		} else {
			var startState = state.indexOf("_off");
			var newClassName = state.substring(0, startState) + "_on";
			div.className = newClassName;

			toggleScreen(true);
		}
	}
}

function toggleScreen(flag) {
	var blackoutElement = document.getElementById("blackout");
	var screenElement = document.getElementById("screen");

	if (flag) {
		blackoutElement.style.display = "none";
		screenElement.style.display = "block";
	} else {
		blackoutElement.style.display = "block";
		screenElement.style.display = "none";
	}
}

function toggleForwardForm() {
	var div = document.getElementById("forwardForm");
	if (div != null) {
		if (div.className == "forwardFormOff") {
			div.className = "forwardFormOn";
		} else if (div.className == "forwardFormOn") {
			div.className = "forwardFormOff";
		}
	}
}

function changeImage(tabName, flag) {
	var activeImage = document.getElementById(tabName + "_active");
	var inactiveImage = document.getElementById(tabName + "_inactive");

	if (flag) {
		activeImage.style.display = "inline";
		inactiveImage.style.display = "none";
	} else {
		activeImage.style.display = "none";
		inactiveImage.style.display = "inline";
	}
}