Welcome to Front Accounting and I am quite new to FA too. I have study FA code and have been trying to hack the code for quite some time. Before you can do this, you should understand how FA works.
To debug FA, you can change the parameters in the file config.php which is located in your frontaccounting folder.
You may change the following parameters to suite your debugging need. 1 mean activated, 0 mean inactive.
$error_logfile = dirname(__FILE__).'/tmp/errors.log';
$debug = 1; // show sql on database errors
$show_sql = 1; // show all sql queries in page footer for debugging purposes
$go_debug = 0; // set to 1 for basic debugging, or 2 to see also backtrace after failure.
$pdf_debug = 0; // display pdf source instead reports for debugging when $go_debug!=0
// set $sql_trail to 1 only if you want to perform bugtracking sql trail
// Warning: this produces huge amount of data in sql_trail table.
// Don't forget switch the option off and flush the table manually after
// trail, or your future backup files are overloaded with unneeded data.
//
$sql_trail = 1; // save all sql queries in sql_trail
$select_trail = 0; // track also SELECT queries
if you activate the $sql_trail = 1, you can check and verify the sql query in the folowing table:
1) 0_sql_trail
You can also copy and paste the sql script from your browser and execute it in MySQL command line.
Hope it help...