function resizeLayer() {
	
	if (hasUndefinedSymbol()) {
		return;
	}
	
	var divSide = document.getElementById("divSide");
	var divMain = document.getElementById("divMain");
	var divFooter = document.getElementById("divFooter");
	
	var bodyHeight = document.documentElement.clientHeight;
	var availHeight = bodyHeight - divSide.offsetTop - divFooter.offsetHeight;
	
	divSide.style.height = availHeight + "px";
	divMain.style.height = availHeight + "px";
}
function hasUndefinedSymbol() {
	if (! document.getElementById("divSide")) {
		return true;
	}
	if (! document.getElementById("divMain")) {
		return true;
	}
	if (! document.getElementById("divFooter")) {
		return true;
	}
	return false;
}