function _e(id) {
	var e = document.getElementById(id);
	if (e == null) {
		var error = new Error();
		error.message = 'Element does not exist';
		error.description = 'The requested element, \'' + id + '\' does not exist as a child within the document object model.';
		throw error;
	}
	return e;
}

function _t(tagName) {
	var t = document.getElementsByTagName(tagName);
	if (t == null) {
		var error = new Error();
		error.message = 'Tag name does not exist';
		error.description = 'No elements within the document object model have the requested tag name, \'' + tagName + '\'.';
		throw error;
	}
	return t;
}

function _loadElementFromURL(element, url, formdata) {
	element.innerHTML = '';

	var r = null;
	try {
		r = new XMLHttpRequest();
	} catch (ex) {
		r = new ActiveXObject('Microsoft.XMLHTTP');
	}

	r.onreadystatechange = function () {
		if (r.readyState != 4 && r.readyState != 'complete') { return; }
		var div = element.cloneNode(false);
		div.innerHTML = r.responseText;
		element.parentNode.replaceChild(div, element);
	}

	r.open('POST', url, true);
	r.send(formdata);
}