// JavaScript Document

function increaseFontSize() {
	var articleheader = document.getElementById("articleheader");
	var articlecontent = document.getElementById("articlecontent");
	setFontSize(articleheader, 0.1);
	setFontSize(articlecontent, 0.1);
}

function decreaseFontSize() {
	var articleheader = document.getElementById("articleheader");
	var articlecontent = document.getElementById("articlecontent");
	setFontSize(articleheader, -0.1);
	setFontSize(articlecontent, -0.1);
}

function setFontSize (root, increment) {
	var BASESIZE = 1;
	var MAXSIZE = 1.9;
	var MINSIZE = 1;
	var currentsize = "";
	var newsize = "";
	
	if (root.style.fontSize) {
		currentsize = parseFloat(root.style.fontSize.match(/\d{1}\.\d{1}/)[0]);
		newsize = currentsize + increment;		
	} else {
		newsize = BASESIZE + increment;
	}
	
	if (newsize <= MAXSIZE && newsize >= MINSIZE) root.style.fontSize = newsize + "em";
}