var min=12;
var max=24;
function increaseFontSize() {
	var elementsArray = ['a','p','li','h1','span','strong','td'];
	for (var x = 0; x < elementsArray.length; x++) {
		var p = document.getElementsByTagName(elementsArray[x]);
		for(i=0;i<p.length;i++) {
			if(p[i].style.fontSize) {
				var s = parseInt(p[i].style.fontSize.replace("px",""));
			} else {
				var s = 12;
			}
			if(s!=max) {
				s += 1;
			}
			p[i].style.fontSize = s+"px"
		}
	}   
}
function decreaseFontSize() {
	var elementsArray = ['a','p','li','h1','span','strong','td'];
	for (var x = 0; x < elementsArray.length; x++) {
		var p = document.getElementsByTagName(elementsArray[x]);
		for(i=0;i<p.length;i++) {
			if(p[i].style.fontSize) {
				var s = parseInt(p[i].style.fontSize.replace("px",""));
			} else {
				var s = 12;
			}
			if(s!=min) {
				s -= 1;
			}
			p[i].style.fontSize = s+"px"
		}	
	}
}