Generally speaking, if the window is large enough to contain the whole image, there won't be a scroll bar. So if the popup is very tall and runs off the bottom of the visible part of the display, that might be the issue.

If you adjust the zoom level of the document in the window, does that affect it? To enlarge, try Ctrl+ once or twice (maybe this will force a scroll bar) and to reduce, try Ctrl- once or twice (maybe this will make the whole image visible).

Another possible issue is that when website pop up specially sized windows they can turn off the scrollbars. You can change a setting so that sites cannot turn off the scrollbars in those windows (but they still could use style rules to suppress them, this won't help with that). Here's how:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste open and pause while the list is filtered

(3) Double-click the dom.disable_window_open_feature.scrollbars preference to switch it from false to true.

Then try popping up another window on the site to see whether it helped.

jscher2000 Thanks for your reply. Have tried both the suggestions you gave, I changed the dom.disable_window_open_feature.scrollbars preference to true, but didn't seem to have any effect. I then played with the 'zoom' level and the only way I can get the whole pop up window in view is to reduce the zoom level, this also reduces the main window size, which now has quite small text etc on it, but i think i can probably live with that...Thanks

If you mean that Lightbox type JavaScript is used to bring up a larger copy of the images then you may not be able to scroll the image if the shown image is larger than the screen.

• http://en.wikipedia.org/wiki/Lightbox_%28JavaScript%29

Did you try the mouse scroll wheel?