function cambiaTab(active, number, tab_prefix, content_prefix) {	
	for (var i=1; i < number+1; i++) {
        document.getElementById(content_prefix+i).style.display = 'none';
        document.getElementById(tab_prefix+i).className = '';
	}
	document.getElementById(content_prefix+active).style.display = 'block';
	document.getElementById(tab_prefix+active).className = 'active';
}