var last_tab = 'tab1';

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

function hide(layerName) {
	document.getElementById(layerName).style.display = 'none';
}
function show_next(tab_name) {
	hideAll();
	document.getElementById(last_tab).className = 'tab';
	var curr = document.getElementById(tab_name);
	curr.className='tab_hover';
	hide(last_tab+'_data');
	show(tab_name+'_data');
	last_tab=tab_name;
}
function hideAll(dt){
	document.getElementById("tab1_data").style.display='none';
	document.getElementById("tab2_data").style.display='none';
	document.getElementById("tab3_data").style.display='none';
	document.getElementById("tab4_data").style.display='none';
	document.getElementById("tab5_data").style.display='none';
	document.getElementById("tab6_data").style.display='none';
	if(dt)
	document.getElementById(dt).style.display='';
}