function trim (str) {
  str = this != window? this : str;
  return str.replace(/^\s+/g, '').replace(/\s+$/g, '');
}

function esEmail(s){
  var email_pattern = /^(\w|-|.|ñ|Ñ)+\@([a-zA-Z0-9]|-)+\.(\w|\.)+/;
  var email_result;
  email_result = email_pattern.exec(s);
  return email_result;
}


var capa_actual=null;
function mostrar_cont(id){
	capa=document.getElementById(id);
	if (capa_actual!=null){
		capa_actual.style.display='none';
		capa_actual = null;
	}	
	if (capa==null) return;
	if (capa.style.display=='block'){
	  capa.style.display='none';
	}else{
	  capa.style.display='block';
	  capa_actual = capa;
	}
}