Thumbnail Images resized inline instead genereted

I don’t have or I just can’t set up thumbnail images on my listings. Right now there are thumbnail images resized in the html (inline width).

Is there w way to pull resized images (which are genereated thumnails not resized by inline html ‘width’? And then when the thumbnail is clicked then the photo will appear in it’s normal size? So in the end there will we two separate images – one small for thumnail and one normal for the photo.

Thanks,
Kris