/* Thanks to http://www.white-hat-web-design.co.uk/blog/controlling-font-size-with-javascript/, this is more browser friendlly*/
var min=16;
var max=22;
function increaseFontSize() {
var p = document.getElementsByTagName('article p');
for(i=0;i<p.length;i++) {
if(p[i].style.fontSize) {
var s = parseInt(p[i].style.fontSize.replace("px",""));
} else {
var s = 16;
}
if(s!=max) {
s += 1;
}
p[i].style.fontSize = s+"px"
}
}
function decreaseFontSize() {
var p = document.getElementsByTagName('p');
for(i=0;i<p.length;i++) {
if(p[i].style.fontSize) {
var s = parseInt(p[i].style.fontSize.replace("px",""));
} else {
var s = 16;
}
if(s!=min) {
s -= 1;
}
p[i].style.fontSize = s+"px"
}
}
<p><a class="smaller" href="javascript:decreaseFontSize();">A</a><a class="larger" href="javascript:increaseFontSize();"><span>A</span></a></p>