imagedestroy problems with memory

Hi there, I am having trouble with ram memory. After about a day the system starts to swap. After doing a bit of research I found that a possible reason could be the missing of the imagedestroy() function. There is a question I have on that. Inside a function I add sometimes watermarks to images, than I return the image from the function. Where would I have to place the imagedestroy command? Inside the function, or after calling it? Here is part of the function code: ######################################### # save image to var to make saving possible in db into blob ob_start(); imagejpeg($photoImage); $photoImage = ob_get_contents(); ob_end_clean(); ######################################### return $photoImage; thankx for any help, Merlin