// Function to handle adding onload events
function addOnLoad(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	} else {
		window.onload = function() {
			oldonload();
			func();
		}
	}
}


// Function to initialize navigation drop-downs
function initNav() {
	if (document.all && document.getElementById) {
		navRoot = document.getElementById("nav");
		for (i=0; i<navRoot.childNodes.length; i++) {
			node = navRoot.childNodes[i];
			if (node.nodeName == "LI") {
				node.onmouseover = function() {
					this.className += " over";
				}
				node.onmouseout = function() {
					this.className = this.className.replace(" over", "");
				}
			}
		}
	}
}

addOnLoad(initNav);


// Function to initialize Search help text
function initSearchHelp() {
	if (document.getElementById) {
		search = document.getElementById("s");
		search.value = "Enter search term(s)";
		search.onfocus = function() {this.value = "";}
	}
}

addOnLoad(initSearchHelp);


// Functions to handle font size switching
function fontSizeSwitch(size) {
	switch (size) {
	  case 'small' :
		document.getElementById('sizeS').className = "on";
		document.getElementById('sizeM').className = "";
		document.getElementById('sizeL').className = "";
		setActiveStyleSheet('Font Size Small');
		break;
	  case 'medium' :
                document.getElementById('sizeS').className = "";
                document.getElementById('sizeM').className = "on";
                document.getElementById('sizeL').className = "";
		setActiveStyleSheet('Font Size Medium');
		break;
	  case 'large' :
                document.getElementById('sizeS').className = "";
                document.getElementById('sizeM').className = "";
                document.getElementById('sizeL').className = "on";
 		setActiveStyleSheet('Font Size Large');
		break;
	  default :
                document.getElementById('sizeS').className = "on";
                document.getElementById('sizeM').className = "";
                document.getElementById('sizeL').className = "";
		setActiveStyleSheet('Font Size Small');
		break; 
	}
}

function setActiveStyleSheet(title) {
	var i, a, main;
	for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
		if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
			a.disabled = true;
			if(a.getAttribute("title") == title) a.disabled = false;
		}
	}
}

function getActiveStyleSheet() {
	var i, a;
	for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
		if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
	}
	return null;
}

function getPreferredStyleSheet() {
	var i, a;
	for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
		if(a.getAttribute("rel").indexOf("style") != -1
			 && a.getAttribute("rel").indexOf("alt") == -1
			 && a.getAttribute("title")
			 ) return a.getAttribute("title");
	}
	return null;
}

function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

function initStyleSheet(e) {
	var cookie = readCookie("abistyle");
	var title = cookie ? cookie : getPreferredStyleSheet();
	setActiveStyleSheet(title);
	document.getElementById('fontsize').innerHTML = '<strong>Text size:</strong> <a href="#" onclick="fontSizeSwitch(\'small\'); return false;" id="sizeS" class="on" title="Smallest Font Size"><span>A</span></a> <a href="#" onclick="fontSizeSwitch(\'medium\'); return false;" id="sizeM" title="Medium Font Size"><span>A+</span></a> <a href="#" onclick="fontSizeSwitch(\'large\'); return false;" id="sizeL" title="Largest Font Size"><span>A++</span></a>';
}

// addOnLoad(initStyleSheet);

window.onunload = function(e) {
	var title = getActiveStyleSheet();
	createCookie("abistyle", title, 365);
}