Hi SB 
  
Thank you to help me. 
Well. Actually I solved the problem in half: it was case sensitive, as follows >> 
  
File Detailed.php >> 
  
 
 
The fix is as follows >>
 
And 
 
  
Result: 
Detailed1.php is displayed (Table and child graph). 
However, the child graph Detailed2.php is not displayed. It displays >> 
 
instead. 
  
File Detailed2.php is coded like this: 
 
  
[EDIT] 
File Detailed2.php is fixed like this: 
 
  
So all work properly now. Many thanks Supreme Being.