var prefsLoaded = false;
var defaultFontSize = 69;
var currentFontSize = defaultFontSize;

function revertStyles()
{
	currentFontSize = defaultFontSize;
	changeFontSize(0);
}


function changeFontSize(sizeDifference)
{
	currentFontSize = parseInt(currentFontSize) + parseInt(sizeDifference * 5);

	if(currentFontSize > 120)
		currentFontSize = 120;
	else if(currentFontSize < 60)
		currentFontSize = 60;

	setFontSize(currentFontSize);
};



function setFontSize(fontSize)
{
	document.body.style.fontSize = fontSize + '%';
	
	//alert (document.body.style.fontSize);
};


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 setUserOptions()
{
	if(!prefsLoaded)
	{
		cookie = readCookie("fontSize");
		currentFontSize = cookie ? cookie : defaultFontSize;
		setFontSize(currentFontSize);
		prefsLoaded = true;
	}
}

function saveSettings()
{
  createCookie("fontSize", currentFontSize, 365);
}

window.onload = setUserOptions;
window.onunload = saveSettings;

/**
 *
 * Example:
 * 
 *	<div id="buttons">
 *		<a href="javascript://" onclick="changeFontSize(2);return false;">A+</a>
 * 		<a href="javascript://" onclick="changeFontSize(-2);return false;">A-</a>
 *		<a href="javascript://" onclick="revertStyles(); return false;">Reset</a>
 *	</div>
 *
 */