How do I register multiple paths for a HttpHandler in IIS7?

Question

I have a HttpHandler that resizes images based on the querystring, so requesting something like:

http://server/image.jpg?width=320&height=240

will give you a resized image that's 320x240.

In the IIS Manager, under Handler Mappings, I mapped my handler's path as *.jpg,*.gif,*.bmp,*.png. However, this doesn't activate the handler. If I change it to just *.jpg, then it works.

My question is, do I have to create 4 separate mapping entries, one for each image type, or is there some way to combine multiple extensions in one path?