How I can Unlink a file

[eluser]hz[/eluser]
Hi
I want o delete a file when its particular record is deleted.
i've simply use the php unlink function to unlink that file.

unlink("images/myimage.jpg");

The code is saved in a php file (htdocs/project/system/application/views/delete.php)
my images are saved in a folder placed on root folder(htdocs/project/images).
I've tried a lot but its continuosly giving me the error that no such file or directory found. What i m doing wrong?