title: Oracle Forms If List of Values Contain No Entries Show Message
body: <p>I have a button and this code in WHEN-BUTTON-PRESSED trigger of button. When I press button, show a LOV. And LOV's query gets result depends on user who press button. I want to show specific message like 'You have no authorization' if list of value gets no entries. But I get error message  "FRM-41830: List of Values contains no entries". What can I do?</p>
  
  <pre><code>DECLARE
     A   BOOLEAN;
  BEGIN
     A := SHOW_LOV ('LIST_OF_VALUE');
  
     SET_BLOCK_PROPERTY (...);
  
     GO_BLOCK ('...');
  
     EXECUTE_QUERY ();
  
     :SYSTEM.message_level := 25;
  EXCEPTION
     WHEN NO_DATA_FOUND
     THEN
        MESSAGE ('You have no authorization');
        :SYSTEM.message_level := 0;
  END;
  </code></pre>