How can i Increase the size of my thumbnail intermediate images?

[stan85in]

When a user clicks on an image, the thumbnail pictures that results along with the description of the pictures is quite small and difficult to see. How do i increase the size of the intermediate pictures? I know it has something to do with changing the size in the theme file but which portion of the theme php should i change. A link to my site is www.ifoundasale.com . After you click on an image you will see what i am talking about. Thanks. Any Help is appreciated.

[Nibbler]

It's a config setting, not related the themes. After you change the setting you will need to rebuild the intermediate images using admin tools.

http://documentation.coppermine-gallery.net/en/configuration.htm#admin_picture_thumbnail_intermediate_dimension