function changeFontSize(inc){  

    
    
        if(document.body.style.fontSize) {       
            var size = parseInt(document.body.style.fontSize.replace("px", ""));    
        } 
        else {       
            var size = 10;    
        }    
        var newsize = size+inc;
        document.body.style.fontSize = newsize + 'px';   
        createCookie('page_size', newsize, 30);
  
}

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 var 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 eraseCookie(name) {
	createCookie(name,"",-1);
}