function updateLetters()
{
	var year = document.getElementById('form_year').value;
	
	var xmlHttp;
	try
	{
		// Firefox, Opera 8.0+, Safari
		xmlHttp=new XMLHttpRequest();
	}
	catch (e)
	{
		// Internet Explorer
		try
		{
			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			try
			{
				xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch (e)
			{
				alert('no support');
				return false;
			}
		}
	}
	
	xmlHttp.onreadystatechange=function()
	{
		if(xmlHttp.readyState==4)
		{
			document.getElementById('mainContent').style.filter = 'alpha(opacity=100)';
			document.getElementById('mainContent').style.opacity = '1';
			document.getElementById('letters').innerHTML = xmlHttp.responseText;
			document.getElementById('year').innerHTML = year;
			document.getElementById('loadingOverlay').style.left = '-1000px'
		}
		else
		{
			document.getElementById('loadingOverlay').style.left = '35%'
			document.getElementById('mainContent').style.filter = 'alpha(opacity=35)';
			document.getElementById('mainContent').style.opacity = '0.35';
		}
	}
	
	xmlHttp.open("GET","/News/Ajax-Letter/Year/" + year + '/rand/' + Math.random(), true);
	xmlHttp.send(null);
}