var fontSize = 12;
var prevSize;

function incFontSize(){
	++fontSize;
	changeFontSize();
}

function decFontSize(){
	if(fontSize <= 0){ return; }
	--fontSize;
	changeFontSize();
}

function changeFontSize(){
	var paragraphs = document.getElementsByTagName('p');
	
	for(var i = 0; i < paragraphs.length; i++){
		paragraphs[i].style.fontSize = fontSize + "px";
	}
	
	var paragraphs = document.getElementsByTagName('a');
	
	for(var i = 0; i < paragraphs.length; i++){
		paragraphs[i].style.fontSize = fontSize + "px";
	}
	
	var bullets = document.getElementsByTagName('li');
	
	for(var i = 0; i < bullets.length; i++){
		bullets[i].style.fontSize = fontSize + "px";
	}
	
	var tablecells = document.getElementsByTagName('td');
	
	for(var i = 0; i < tablecells.length; i++){
		tablecells[i].style.fontSize = fontSize + "px";
	}

	var heads1 = document.getElementsByTagName('h1');
	
	for(var i = 0; i < heads1.length; i++) {
		heads1[i].style.fontSize = (fontSize*4) + "px";
	}
	
	// Don't do anything with H2s, these are used for Quick Links + Case Study
	// H2s are not used anywhere else - H3s instead.
	
	var heads3 = document.getElementsByTagName('h3');
	
	for(var i = 0; i < heads3.length; i++) {
		heads3[i].style.fontSize = (fontSize*1.5) + "px";
	}
	
	// Lazily copy-pasted from the Green Tool (under Resources):
	// Saves for 2 months
	var date = new Date();
	date.setTime(date.getTime()+(60*24*60*60*1000));
	document.cookie = "ecoFontSize=" + fontSize + "; expires=" + date.toGMTString() + "; path=/";
	
	document.getElementById('menufive').fontSize = "16px";
}

// Read Cookie function used with permission
function chooseCorrectCookie(){
	var cookieData = document.cookie;
	var cookies = cookieData.split(";");
	var j = -1;
	for(var i = 0;i<cookies.length;i++){
		if(cookies[i].indexOf("ecoFontSize=") != "-1"){
			j = i;	
		}	
	}
	if(j != -1){
		return cookies[j];
	} else {
		return j;
	}
}

function load(){
    savedData = chooseCorrectCookie();
    if(savedData == ""){ return; }
    var cookieFont = savedData.substr(savedData.indexOf("=") + 1);
    if(cookieFont){
	    if(parseInt(cookieFont) > 0 && parseInt(cookieFont) < 100){
		    fontSize = cookieFont;
		    changeFontSize();		
	    } 
    }
}

load();