var min_size = 0.8;
var max_size = 1.6;

var last_size = 1.2;

var change_fontsize = function(delta) {
	var elm = document.getElementById('main_text');
	if (elm) {
		last_size += delta;
		if (last_size < min_size) {
			last_size = min_size;
		} else if (last_size > max_size) {
			last_size = max_size;
		}
		elm.style.fontSize = last_size + 'em';
	}

	$(function() {
		$('.scroll-pane').jScrollPane();
	});
}