title: Update an observable value when other observable value changes in knockout
body: <p>I have the following  view:</p>
  
  <pre><code>&lt;div class="form-group"&gt;
      &lt;label&gt;Company Name&lt;/label&gt;
      &lt;input type="text" class="form-control" data-bind="text: $root.CompnayNameFilter"&gt;
  &lt;/div&gt;
  &lt;div class="form-group"&gt;
      &lt;label&gt;Phone Number&lt;/label&gt;
      &lt;input type="text" class="form-control" data-bind="text: $root.PhoneNumberFilter"&gt;
  &lt;/div&gt;
  &lt;div class="form-group"&gt;
      &lt;label&gt;User Name&lt;/label&gt;
      &lt;input type="text" class="form-control" data-bind="text: $root.UsernameFilter"&gt;
  &lt;/div&gt;
  &lt;div class="form-group"&gt;
      &lt;label&gt;Database Location&lt;/label&gt;
      &lt;input type="text" class="form-control" data-bind="text: $root.DatabaseLocationFilter"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I have the following view model:</p>
  
  <pre><code>var viewModel = {
      CompnayNameFilter: ko.observable(),
      PhoneNumberFilter: ko.observable(),
      UsernameFilter: ko.observable(),
      DatabaseLocationFilter: ko.observable(),
      DoFilterOnFilteredData:ko.computed(function(){
            // code to update DoFilterOnFilteredData to false when any other observable changes
      })
  }
  </code></pre>
  
  <p>My requirement is that whenever user enters a new value or changes the value in the <code>Company Name</code>, <code>Phone Number</code>, <code>User Name</code> and <code>Database Location</code> textboxes, I have to set the <code>DoFilterOnFilteredData</code> value to false. How can I achieve this? I think this is possible using a computed observable.</p>
  
  <p>P.S: If possible, please provide a fiddle for this. </p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>JSFiddle: <a href="http://jsfiddle.net/seadrag0n/dytre/" rel="nofollow">http://jsfiddle.net/seadrag0n/dytre/</a></p>