last_tab = 'content_rs';
function show(layerName) {
document.getElementById(layerName).style.display = '';
}

function hide(layerName) {
document.getElementById(layerName).style.display = 'none';
}

function show_next(tab_name) {
//document.getElementById(last_tab).className = 'tab';
var curr = document.getElementById(tab_name);
//curr.className='tab_hover';
hide(last_tab);
show(tab_name);
last_tab=tab_name;
}