var winW
var winH
function meret() {
	winW = document.viewport.getWidth()
	winH = document.viewport.getHeight()
	winW = (winW-800)/2;
	if (winW < 0) {
		winW = 0
	}
	//document.getElementById('mainDiv').style.paddingLeft = winW+"px"
	document.getElementById('meretezo').style.height = winH+"px"
}