UpdateProfile. Как изменить имя пользователя

 [[+fullname]]

[[+username]] 

 <label for="fullname">[[!%login.fullname? &namespace=`login` &topic=`updateprofile`]]
<span class="error">[[+error.fullname]]</span></label>
<input id="fullname" type="text" name="fullname" value="[[+fullname]]" /> 

 <label for="username">[[!%login.username? &namespace=`login` &topic=`updateprofile`]]
<span class="error">[[+error.username]]</span></label>
<input id="username" type="text" name="username" value="[[+username]]" /> 

$qurName='vasya';
$newName='Nyaka';
$uName=getObject('modUser',array('username'=>$qurName));
$uName->set('username',$newName);
$uName->save();