window.onload = function() {  
	var news1 = document.getElementById('tab_1');
	var news2 = document.getElementById('tab_2');
	var news3 = document.getElementById('tab_3');
	if (news1)
	{	news1.onclick = function() {
			document.getElementById('top_news').className='active_1';
			return false;
		}
	}
	if (news1)
	{
		news2.onclick = function() {
			document.getElementById('top_news').className='active_2';
			return false;
		}
	}
	if (news1)
	{
		news3.onclick = function() {
			document.getElementById('top_news').className='active_3';
			return false;
		}
	}
}