function fontsize(sizeMode) {
	var sizes = new Array(10,11,12,14,16,18);
	bodyObj = document.getElementsByTagName('body');
	if(bodyObj[0].style.fontSize != '')
		var s = parseInt(bodyObj[0].style.fontSize.replace("px",""));
	else
		var s = 12;

	if(sizeMode == 'decrease')
		offset = -1;
	else
		offset = 1;

	for(i=0;i<=sizes.length;i++) {
		if(sizes[i+offset] && sizes[i] == s) {
			bodyObj[0].style.fontSize = sizes[i+offset]+'px';
		}
	}
}