var lastpanel = null;
var lasttab = null;

function hidelast() {
	if (lastpanel != null && lasttab != null) hidePanel(lastpanel, lasttab);
	return false;
}

function showPanel(panel, ptab) {
	hidelast();
	$(panel).style.visibility = "visible";
	$(ptab).setStyle('background-color:white;');
	lastpanel = panel;
	lasttab = ptab;
	return false;
}

function hidePanel(panel, ptab) {
      $(panel).style.visibility = "hidden";
	  $(ptab).setStyle('background-color:transparent;');
	  return false;
}