function obj_vis (obj_id) {
	
	document.getElementById('popup_1').style.visibility = 'hidden';
	document.getElementById('popup_2').style.visibility = 'hidden';
	document.getElementById('popup_3').style.visibility = 'hidden';
	document.getElementById('popup_4').style.visibility = 'hidden';

	//document.getElementById('leer').style.visibility = 'hidden';
	document.getElementById('leer').style.display = 'none';

	document.getElementById(obj_id).style.visibility = 'visible';
}