function collapse(id) {
	var article = document.getElementById('' + id);
		if(article.style.display == 'none') {
		article.style.display = 'block';
		}
		else {
		article.style.display = 'none';
		}
	}
function multi_collapse(first,second) {
		document.getElementById(first).style.display = 'block'
		document.getElementById(second).style.display = 'none';
}