var tab_years = new Array ();
tab_years[1000] = 'tMac';
tab_years[1001] = 'tWindows';



function hide_element(id)
{
	var e = document.getElementById(id);
	e.style.display = 'none';
	return;
}

function show_element(id)
{
	var e = document.getElementById(id);
	e.style.display = 'block';
	return;
}

function select_tab(year)
{
	var atab = tab_years[year];
	var ae = document.getElementById(atab);
	
	for(var i=1000; i <= 1001; i++)
	{
		var tyear = tab_years[i];
		var e = document.getElementById(tyear);
		
		if(e)	// if tXXXX exists
		{
			e.className = 'four unselected';
			hide_element(i);
		}
	}
	
	ae.className = 'four selected';
	show_element(year);
	
	return;
}