title: Update element from user profile in Meteor
body: <p>I am trying to update <code>firstName</code> field created in <code>user.profile</code> using <code>onCreateUser</code>:</p>
  
  <pre><code>Accounts.onCreateUser(function(options, user) {
      user.profile = options.profile || {};
      user.profile.firstName = options.firstName;
      return user;
  });
  </code></pre>
  
  <p>Also I use allow:</p>
  
  <pre><code>Meteor.users.allow({
      update: function(userId, doc, fields, modifier) {
          if (fields === "profile.firstName") {
              return true;
          }
      }
  });
  </code></pre>
  
  <p>When I use: </p>
  
  <pre><code>Meteor.users.update({
      _id: Meteor.userId()
  }, {
      $set: {
          profile: "George"
      }
  });
  </code></pre>
  
  <p>It works but it is not what I need.</p>
  
  <p>What I need is to update <code>firstName</code>:</p>
  
  <pre><code>Meteor.users.update({
      _id: Meteor.userId()
  }, {
      $set: {
          profile.firstName: "George"
      }
  });
  </code></pre>
  
  <p>But I get this error:</p>
  
  <blockquote>
    <p>SyntaxError: missing : after property id</p>
  </blockquote>
  
  <p>What am I missing?</p>