file delete problem

[eluser]rubai[/eluser]
hi there
i am trying to delete one file from localhost.
but it fails.
i write:

Code:

delete_files($_SERVER['DOCUMENT_ROOT'].'/project/uploads/'.$exists_image);

where $exists_image is the file name.
but if i print the code it shows the right path.
for example

Code:

C:/apachefriends/xampp/htdocs/project/uploads/image.jpg

is my code wrong?