1) Open your subreport and in the details section where you displaying all the fields.
2) Choose one of the fields that you want to show it Let's say for example the field name is "EMP_NAME".
Make sure that this "EMP_NAME" field will not have any data when you want "Not Available Data" message to be shown, otherwise will have data so "Not Avaliable Data" will not be shown.
If you want your message to be shown when your subreports will have empty data. other wise it always have data then no problem choose any field you want from your subreport.
3) Put the message "Not Available Data" as a text in details section.
4) Right Click on this text and choose "Format Field".
5) In the Common Tab tick the checkbox that is next to Suppress.
6) Click on the icon beside the Suppress and in the dialogbox that will be opened type this Formula:
if "EMP_NAME" = "" then
True
else
False
So when you insert this subreport in your main report it will show the data if there is data, if not then it will show your message "Not Available Data".
Ibtisam.