function GO()
{
	<!-- Define number of header images name them header+number starting with 0-->
	var nrHeaders = 4;
	document.getElementById('banner').src = "http://www.mjuks.nl/wp-content/themes/mjuks/images/headers/header" + Math.floor(Math.random() * nrHeaders) + ".png" ;
	<!-- Grab footer y-coordinate and stretch the container height to fit -->
	var hOff = document.getElementById('footer').offsetTop - 223;
	document.getElementById('container').style.height = hOff + "px";
}
function checkForm()
{
	if((document.getElementById('author').value.length >= 2) && (document.getElementById('email').value.length >= 5) && (document.getElementById('comment').value.length >= 3))
	{
		if((document.getElementById('email').value.indexOf("@") > 1) && (document.getElementById('email').value.indexOf(".") > (document.getElementById('email').value.indexOf("@") + 2)))
		{
			document.getElementById('submit').disabled = false;
		}
		else
		{
			document.getElementById('submit').disabled = true;
		}
	}
	else
	{
		document.getElementById('submit').disabled = true;
	}
}