/**
 * Adds functions into window.load / onload event handlers
 * rather than writing over it.
 * 
 * http://www.sitepoint.com/article/javascript-from-scratch/2
 * http://simon.incutio.com/archive/2004/05/26/addLoadEvent
 */
function addLoadListener(fn)
	{
	if (typeof window.addEventListener != 'undefined')
		{
		window.addEventListener('load', fn, false);
		}
	else if (typeof document.addEventListener != 'undefined')
		{
		document.addEventListener('load', fn, false);
		}
	else if (typeof window.attachEvent != 'undefined')
		{
		window.attachEvent('onload', fn);
		}
	else
		{
		var oldfn = window.onload;
		if (typeof window.onload != 'function')
			{
			window.onload = fn;
			}
		else
			{
			window.onload = function()
				{
				oldfn();
				fn();
				};
			}
		}
	}


// getElementById returns null if there is no item with that id.

function get_id_reference(id_target)
	{
	//alert(id_target);
	return document.all ? document.all[id_target] : document.getElementById(id_target);
	}



function get_id_reference2(id_target)
	{
	if (document.getElementById)
		{
		return document.getElementById(id_target);
		}
	else if (document.all)
		{
		return document.all[id_target];
		}
	else if (document.layers)
		{
		return document.layers[id_target];
		}
	}