function update() {
	var r = $e('r').value;
	var fp = $e('fp').value;
	var ne = $e('ne').value;
	var fl = $e('fl').value;
	var fi = $e('fi').value;
	var fc = $e('fc').value;
	var L = $e('L').value;	
	var p = r*fp*ne*fl*fi*fc*L;
	var solution = $e('solution');
	solution.innerHTML = "Number of civilizations = " + p;
	return;
}	

function $e(el) {
	return document.getElementById(el);
}

window.onload = window.setTimeout("update()", 500);