I'm importing over 8,000 products into my site via an excel file and even though most product images will be named according to their product number I'm sure there will be some that do not get named correctly or are not found at all so I would like the no_image gif to show up instead of a broken image.

I know there has to be a modification done to the image_function file I'm just not sure how, I'm not much of a php coder, I can understand it but cannot write it. Something like if image not found display no_image.gif

Can anyone help, please?