The "Close" Button on new windows

is it really necessary?

[microcars]

I have a site with lots of photos and each main page brings up a splash image with a description and then there are a group of thumbnails.

If you click on a thumbnail, it opens a 640x480 window that contains the image and the title bar and that's it.
This floats above the main page in the upper left hand corner.

I've been doing this for some time now and not heard any complaints from the client or anyone else, so....I'm on a Mac, there is always an option to close the window, is an ADDITIONAL "Close" Button really necessary and if so, what circumstances require it?

[deejay]

I don't think it's really 'necessary', but it can be a nice finishing touch.

... and there are always those newer users who are stymied when they can't get to 'file', 'close' in a pop-up window (I've seen two last week who just don't connect with the 'X' button at all.

Personal preference at the end of the day.