var currentLayer = 'page1';

function showPageLayer(layer,tab) {
	 hideLayer(currentLayer);
   showLayer(layer);
   currentLayer = layer;
   highlightTab(tab);
}

function hideLayer(lyr) {
   document.getElementById(lyr).style.display = 'none';
}

function showLayer(lyr) {
   document.getElementById(lyr).style.display = 'block';
}

function highlightTab(x) {
	tabs = document.getElementById("tabnav").getElementsByTagName('li');
	for(i=0; i<tabs.length; i++) {
		tabs[i].className = tabs[i].id;
	}
	tabs[x].className = tabs[x].id + "-highlight";
	tabs[x].getElementsByTagName('a')[0].blur();
}