Event.observe 
(
 	window,
	'load',
	function ()
	{
		attachEvents ();
	}
);

function attachEvents ()
{
	var submitButtons = document.getElementsByClassName ('submit-button');
	
	submitButtons.each
	(
		function (element)
		{
			Event.observe
			(
				element,
				'click',
				function ()
				{
					displayLoader ();
				}
			);
		}
	);
}

function displayLoader ()
{
	var submitButtons = document.getElementsByClassName ('submit-button');
	
	submitButtons.each
	(
		function (element)
		{
			Element.setStyle
			(
				element,
				{
					display: 'none'
				}
			);
		}
	)
	
	Element.setStyle
	(
		$ ('submit-loader'),
		{
			display: 'inline'
		}
	);
}