From Journal Entry:
1. Select Tools, Options from menu bar
2. Select the Records tab
3. Highlight Post Options under Journal Entry
4. For Print Post Report on next the a printer name, select Preview post report from the drop-down menu
5. Click Apply, OK

From Administration:
1. Open the Post parameters
2. Select the Format tab
3. Select Preview Post Report instead of Print Post Report On from the drop-down menu