When passed the name of an existing window, window.open will always open a new tab instead of replacing the contents of that existing window.
I have seen people with this issue in Windows 8 and Server 2012, but I am on Windows 7.
All pages involved are from the same web application running on localhost. They are all in the Intranet security zone.
Adding the fourth parameter of "True" to window.open does not change anything. Plus that will break for any of our clients who try to run this in earlier versions of .Net.
Has anyone found a solution to this?