loading.js

This is the script which used on 10minutemail.com for temporary email.

/**
 * Default loading implementation
 *
 * @category	HTML
 * @package	Ajax
 * @license	http://www.opensource.org/licenses/lgpl-license.php  LGPL
 * @copyright	2005 Joshua Eichorn
 * see Main.js for license Author details
 */
HTML_AJAX.Open = function(request) {
	var loading = document.getElementById('HTML_AJAX_LOADING');
	if (!loading) {
		loading = document.createElement('div');
		loading.id = 'HTML_AJAX_LOADING';
		loading.innerHTML = 'Please wait while loading...';
		
		loading.style.color	 = '#fff';
		loading.style.position  = 'absolute';
		loading.style.top   = 0;
		loading.style.right	 = 0;
		loading.style.backgroundColor = '#f00';
		loading.style.border		= '1px solid #f99';
		loading.style.width		 = '80px';
		loading.style.padding	   = '4px';
		loading.style.fontFamily	= 'Arial, Helvetica, sans';
		loading.count = 0;
	
		document.body.insertBefore(loading,document.body.firstChild);
	}
	else {
		if (loading.count == undefined) {
			loading.count = 0;
		}
	}
	loading.count++;
	if (request.isAsync) {
		request.loadingId = window.setTimeout(function() { loading.style.display = 'block'; },0);
	}
	else {
		loading.style.display = 'block';
	}
}
HTML_AJAX.Load = function(request) {
	if (request.loadingId) {
		window.clearTimeout(request.loadingId);
	}
	var loading = document.getElementById('HTML_AJAX_LOADING');
	loading.count--;

	if (loading.count == 0) {
		loading.style.display = 'none';
	}
}