cpanel error pages

i have 400,401,403,404,500 shtml pages in root. php, oscommerce, mysql. all the shtml pages works perfect but 500. today, i realized after i made a mistake in php coding one of file of site. an error occured like below and explorer error page loaded, not my 500 shtml, if this php code mistake produces diffrent error from 500 errro, than which error returns.
i could not find in forums and manuel.

14-Oca-2012 19:17:16] PHP Parse error: syntax error, unexpected T_STRING in /home/example/public_html/catalog/includes/modules/boxes/bm_whats_new.php on line 82

 

http://www.mysite.com:2052/cpsess64444451393/frontend/x3/index.html?
i connect cpanel with an address like above. i can not see examples directory with cutftp or someaddress in cpanel. i have read the documents in cpanel but no specific reply. what i need is to give an error message if i make a mistake in php coding. my point of view i could not anything in web or, cpanel manuels.

 

sthml pages can be seen in root by ftp programms. i meaned if i create one, than it is in root. i did not search anything in root. as a manager of web site a cpanel password and user name assigned.
i connect with this address. so i can not see anything like example in cpanel or /home/example/public_html/ connecting with ftp. i mean i can not see one directory above. i read the document from c panel, looked for in the net. i think it is impossible to produce error page for code mistakes. if there is a mistake php string, or ; than white page comes.