title: SUM() on a form footer resulting in #Error
body: <p>I'm trying to display the sum of a field in a text box in the form footer.  The field is not calculated in any way.</p>
  
  <p>Here are a couple of the things I've tried:</p>
  
  <pre><code>=Sum([txtWeldInches])
  =Sum([WeldInches])
  =Sum(CDbl([txtWeldInches]))
  =Sum(CDbl([WeldInches]))
  </code></pre>
  
  <p>...well you get the idea.  Each iteration I've used results in the Text Box displaying #Error Without exception.</p>
  
  <p>I've used similar constructs in different forms in the same project, so I'm not sure what the problem might be.</p>
  
  <p>Has anyone run into this before?</p>
  
  <p>EDIT:
  I ended up writing a VBA routine to update the boxes when it was likely that they would be changed rather than trying to get a bound sum() function to work.</p>