function increaseFont(){
	myHTML = document.getElementsByTagName('html');
	for(i=0; i<myHTML.length; i++){
		current = parseFloat(myHTML[i].style.fontSize);
		if(isNaN(current)){
			newSize = 72.5;
		}
		else{
			newSize = current + 10;
		}
		myHTML[i].style.fontSize = newSize + "%";
	}
}
	
function decreaseFont(){
	myHTML = document.getElementsByTagName('html');
	for(i=0; i<myHTML.length; i++){
		current = parseFloat(myHTML[i].style.fontSize);
		if(isNaN(current)){
			newSize = 52.5;
		}
		else{
			newSize = current - 10;
		}
		myHTML[i].style.fontSize = newSize + "%";
	}
}