title: Create OpportunityProduct using REST
body: <p>I'm trying to create a new OpportunityProduct using this rest call:</p>
  
  <pre><code>XRMServices/2011/OrganizationData.svc/OpportunityProductSet
  
  {"ProductId":"ef71ce8e-1ef3-e211-b252-984be17c47e4","Quantity":123,"ProductDescription":"Added from code - TEST123","OpportunityId":"8bdb3525-7274-e311-a90b-6c3be5be5f78"}
  </code></pre>
  
  <p>The call returns: </p>
  
  <blockquote>
    <p>The request should be a valid top-level resource object.</p>
  </blockquote>
  
  <p>This indicates that my arguments is not correct. I see to possible reasons for this:</p>
  
  <ol>
  <li>I'm missing some required properties (How can I figure out which is required?)</li>
  <li>It is not possible to do using rest</li>
  </ol>
  
  <p>(both guids are returned via other call and should be correct)</p>
  
  <p>Any help would be great!</p>
  
  <p>Thanks</p>
  
  <p>Larsi</p>