title: Breeze/Knockout dropdown value is not updated in database if caption is selected instead of value
body: <p>I am using Breezejs with Durandal in my .net application.</p>
  
  <p>When i try to edit a section which contains</p>
  
  <p>1) Text box</p>
  
  <p>2) Dropdownlist with caption and options
  </p>
  
  <p>3) TextArea</p>
  
  <p>4) Button</p>
  
  <p>Onclick of edit button, i am binding these controls with their respective values(till then it works fine).</p>
  
  <p>After i change textbox value to "test123" and dropdown values to it's "caption" and clicking on save button. In save function I am creating Breeze entity in modified state and updating them as shown below,</p>
  
  <pre><code>var personEntity = breeze.manager.createEntity('TableName', { Id: id }, breeze.EntityState.Unchanged);
  personEntity.entityAspect.entityState.setModified();
  personEntity.name(name); //"test123"
  personEntity.dropdownValue(status) //I have selected the caption, means value is undefined
  personEntity.textArea(address); //No change
  </code></pre>
  
  <p>then making savechanges() to DB.</p>
  
  <p>In table text box value is updated properly but the value of dropdownlist is not updated(from some value 
  to Null);</p>
  
  <p>Kindly suggest me some solution so that i can save null value in DB if caption is selected.</p>
  
  <p>Thanks in Advance......</p>