Center Images Vertically & Horizontally

size.js

$(window).load(function () {
	var button_w = $('#button img').height();
	var button_h = $('#button img').width();
	var margin_left = button_w / 2 * -1;
	var margin_top = button_h / 2 * -1;
	$('#button').css('marginLeft', margin_left);
	$('#button').css('marginTop', margin_top);
});