I have several sets of php code that need to be inserted to displayimage.php, what do i put in the codebase to achive this?
Thanks,
			
			
			
				You don't. Use the provided plugin hooks and filters or provide instructions to the user about what hooks/filters to add if there are none suitable.
			
			
			
				Ok, so i would use 
Quote$thisplugin->add_filter('file_footer','vhp_file_footer');
to apply the code to displayimage.php.
But i still dont understand how to add code to a specific location example: "code on line 403 of upload.php"
How do i do this? 
Thanks,
			
				You don't. That's what makes a plugin different to a mod. If you need people to make code changes then write it up as a mod instead. Not everything can be made into a plugin,
			
			
			
				Ok, a mod it is. 
Thanks,