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 false;
}
function setFONT(setF){
	var sizeUnit = "%", defaultSize = 57;
	var changeValue = 10;
	minSize = 37;
	maxSize = 87;
	switch(setF){
		case "-":{
			var fontS = readCookie('fontSize');
			if(!isNaN(parseFloat(fontS)))
				fontS -= changeValue;
			else {
				defaultSize -= changeValue;
				fontS = defaultSize;
			}
			if(fontS<minSize)
				fontS = minSize; 
			break;
		}
		case "+":{
			var fontSize = parseFloat(readCookie('fontSize'));
			if(!isNaN( parseFloat(fontSize)))
				fontS = fontSize + changeValue;
			else {
				defaultSize += changeValue;
				fontS = defaultSize;
			}
			if(fontS>maxSize)
				fontS = maxSize; 
			break;
		}
		default:{
			if(setF){
				if(setF>maxSize || setF<minSize)
					fontS = defaultSize;
				else
					fontS = setF;
			}
			else
				fontS = defaultSize;
			break;
		}
	}
	document.body.style.fontSize = fontS+sizeUnit;
	createCookie('fontSize',fontS,365);
}
function switchCSS(css){
	createCookie('style',css,365);
	location.reload();
}
function setCSS(css){
	var link_ = document.getElementsByTagName("link");
	for ($i=0;$i<link_.length;$i++)
		if(link_[$i].media=="screen" && link_[$i].title=="Foglio di stile principale")
			link_[$i].href=css;
}

window.onload = function(e){
	var fontSize = readCookie('fontSize');
	if(fontSize)
		setFONT(fontSize);
	var css = readCookie('style');
	if(css && css == 'style/contrast.css')
		setCSS(css);
}