https://github.com/feb0223/1pixelTestSample201306_01 jQuery 1.7らしく

modal.js

(function(w) {
var model = {
  getDetail: function(callback) {
		$.getJSON('./detail.json')
			.done(function(data) {
				callback(data);
			});
	}
};

var View = (function() {
	/**
	 * @constructor
	 */
	function View() {
		this.main = $('#main');
		this.btnShowModal = $('#btn_show_modal');
	}

	View.prototype.createModalWindow = function(detail) {
		var rawModalWindowNode = document.createElement('div');
		rawModalWindowNode.innerHTML = [
			'<div class="modal-header">',
			'<h3 class="title">' + detail.title + '</h3>',
			'</div>',
			'<div class="modal-body">',
				'<p class="description">' + detail.description + '</p>',
			'</div>',
			'<div class="modal-footer">',
				'<button class="btn btn_close">Close</button>',
			'</div>'
		].join('');
		var modalWindowNode = $(rawModalWindowNode);
		modalWindowNode.find('.btn_close').data('modalNode', modalWindowNode);
		return modalWindowNode;
	};
	return View;
})();

$(document).ready(function() {
	var view = new View();

	view.btnShowModal.on(
		'click',
		function(e) {
			model.getDetail(function(detail) {
				var modalWindow = view.createModalWindow(detail);
				view.main.append(modalWindow);
			});
		}
	);

	view.main.on(
		'click',
		'.btn_close',
		function(e) {
			$(this).data('modalNode').remove();
		}
	);
});

})(window);