Upload image file name probelm

When I add a product with uploading a image file, if the file name exists in same directory, the old file will be overwritten, and cause the correlative old product use this new image file.

How to avoid this?

When I add a product with uploading a image file, if the file name exists in same directory, the old file will be overwritten, and cause the correlative old product use this new image file.

How to avoid this?
Use unique filenames for your images

kobra:

Use unique filenames for your images

I know this is ok, but I think system make it unique is a better method.

The default script does not perform this - - but it is open source so you can extend it to do what ever you think is important