last_tab = 'tab1';
last_tabsub = 'subtab1';

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 = '';
		
	var curr = document.getElementById(tab_name);
		
	curr.className='current';
	hide(last_tab+'_data');
	show(tab_name+'_data');
	last_tab=tab_name;
}

function show_div(tab_name)
{
 	for(i=1;i<=4;i++)
    {
        var cur_tab = "tab"+i;
        var cur_info = "tab"+i+"_info";

        if(cur_tab == tab_name)
        {
            show(cur_tab);
            hide(cur_info);
        }
        else
        {
            hide(cur_tab);
            show(cur_info);

        }
    }
}