Fitting an image inside a panel

I have places an image inside an panel and I am wondering if it possible somehow to have the image automatically be resized to fit inside the panel without scrollbars and such. For now I dont mind even if it means streching out the image in a bad way although if that could be avoidable it would be an plus.

I think this addone you are searching for:

Looks great, thanks.

Just to give my 2 cents, this can be done by setting the image width to 100% like so: