using file_exists with paths - assistance please

[bradoirs]

Assistance please

Desparately trying to implement file_exists but really struggling with the paths

basically my php app will be:

http://www.davidstuff.co.uk/workingon/wordapps/MainLetter.php

The images to check for (as an example) will be

http://www.davidstuff.co.uk/workingon/imageslib/p154.jpg

Any suggestions welcomed - very new to PHP and have taken the easy route of having files and code in same directory but need to get to grips with central store for image files.

 

[jpadie]

if(file_exists('../imageslib/p154.jpg')):
//do something
endif;

or

if(file_exists($_SERVER['DOCUMENT_ROOT'] . '/workingon/imageslib/p154.jpg')):
//do something
endif;

or loads of other ways.