title: How to display another value if the column is null?
body: <p>I am new to Birt reporting.
  My requirement is that, I want to display "N/A" when the actual value of the column is null.</p>
  
  <p>For ex: <code>select vendor from account where id=1;</code></p>
  
  <p>o/p: NULL</p>
  
  <p>so, in place of null  values in the report I want to display those fields as N/A. How to do this?</p>