delete a file after headers sent

[PapRika]

I have this part of a code that generates a image file and send it to the browser to open / download.
When the user opens the file, automaticallt the script unlinks 9deletes) the file. So what's tje worry? if the user DOESN'T do anything or cancels file transfer, the file stays!! I want to prevent this because it's a temp file.
Sosmebody?

case 'convert':

			$path = "c:/temp/";

			$gebruiker="gast";
			$time=time().smarteye;
			$image="motor.jpg";

            	                            $convert=$convert=`convert $image $time.$format`;
			$bestandsnaam= $time.".$format";
			header('Content-type: application/pdf');
			header('Content-Disposition: attachment; filename="' . $bestandsnaam . '"');
			readfile("$bestandsnaam");
							unlink ("$bestandsnaam");



				break;

[DonChris]

$content=implode("",file("$bestandsnaam"));
unlink ("$bestandsnaam");
echo $content;

[PapRika]

the file still stays on fileserver after cancelling download/open the file.