In Joomla 1.6, the “?tp=1″ function to view the layout elements of the template is disabled by default.
1. Log into Joomla backend
2. Navigate to: Extensions > Templates
3. On the top right click > Options > Template Tab > Select “Enabled”
* Preview Module Positions: Enabled
4. Save and close
Go to the front end of your site and add ?tp=1 after the domain name i.e. http://mydomain.com/?tp=1
Hope this helps