title: Updating an observable on key press and click event
body: <p>I have a value binding that looks like this:</p>
  
  <pre><code>&lt;textarea class="form-control" placeholder="Comments" rows="10" data-bind="value: $root.GetTabComment($data).Comment, valueUpdate: 'keyup'"&gt;&lt;/textarea&gt;
  </code></pre>
  
  <p>The reason I use <code>keyup</code>, is because I have a "save as you type" system set up. This works great as the user is typing, but if they correct spelling through spell check (using mouse clicks and no keyboard at all), the binding will not update. </p>
  
  <p>The bound variable Comment is declared as:</p>
  
  <p><code>Comment = ko.observable("").extend({throttle: 1000})</code></p>
  
  <p>And the subscription is simply:</p>
  
  <pre><code>Comment.subscribe(function(){
    //save code
  });
  </code></pre>
  
  <p>Is there some way for me to force the binding to take on the current value of the text area when a button is clicked?</p>