function CUshow(which){
	//alert ( which );
	hideCurrentPopup();
	if (!document.getElementById) return false;
	document.getElementById(which).style.display="block"
	return true;
}
function CUhide(which){
	if (!document.getElementById) return false;
	document.getElementById(which).style.display="none"
	return true;
}
function hideCurrentPopup() {
    // note: we've stored the currently-visible popup on the global object window.currentlyVisiblePopup
    if(window.currentlyVisiblePopup) {
	var isVisible = CUhide(window.currentlyVisiblePopup);
//alert ( "HIDE " + window.currentlyVisiblePopup)
	window.currentlyVisiblePopup = false;
    }
} // hideCurrentPopup