var activeInfoDiv = null;
function changeInfoDiv(div) {
	if(!arguments[0] && activeInfoDiv) {
		document.getElementById(activeInfoDiv).style.display = 'none';
		activeInfoDiv = null;
	}
	else if(div != activeInfoDiv) {
		if(activeInfoDiv) {
			document.getElementById(activeInfoDiv).style.display = 'none';
		}
		document.getElementById(div).style.display = 'block';
		activeInfoDiv = div;
	}
}