"Reset to Original Size" Setting an image to new size

"Reset to Original Size"

I changed the size of the buttons on my web site.  So I'm having to go into each image:

• Select it.
• Move the cursor to the properties window and click on the crossed circle to ge teh image to switch to the new size.

Is there a way to to the entire page or is there a way to select all the images and set to original size all at once?

Your help is deeply appreciated.

Michael