function show(elementid) { 
	hideallnews();
	document.getElementById(elementid).className = "montrer";
}

function hideallnews() {
	document.getElementById('bt_news_0').className = "cacher";
	document.getElementById('bt_news_1').className = "cacher";
	document.getElementById('bt_news_2').className = "cacher";
	document.getElementById('bt_news_3').className = "cacher";
	document.getElementById('bt_news_4').className = "cacher";
	document.getElementById('bt_news_5').className = "cacher";
}