var newwindow;
function avaakuva(url) {
	topVal = (screen.height-650) / 2;
	leftVal = (screen.width-750) / 2;
	newwindow=window.open(url,'KoivuniemenTila','width=750,height=650,left='+leftVal+',top='+topVal+'');
	if (window.focus) {newwindow.focus()}
}