I warned the user beforehand and opened the new window at 80% height and width of the original window to show it was a new window.
However I can't seem to control XLS, DOC, RTF documents. These are the issues:
1. Firefox: They always seem to open in a new window anyway.
3. IE and Firefox: I can't seem to control the height and width
Any suggestions (please don't say don't open new windows - I am under instructions to do this).