Affects: IE10 "Metro" on Windows 8
Note this bug affects "Metro" (and we need to use air quotes because Microsoft has not clarified what this new OS mode will be called after Metro AG staked their legal claim to the copyright name).
One of the many changes in IE10 "Metro" is that not only do plugins no longer work (with the exception of a minor chance of running Adobe Flash) but some basic functionality has been removed.
In IE10 Metro the window.prompt(msg, default); method no longer works - period.
alert('Your username is: ' + username);
In all browsers this will alert the username that the user enters however now in IE10 "Metro" this method is technically defined however it will never show the prompt and will return undefined.
We find it humorous that after supporting the method badly for over a decade Microsoft chose to drop the method completely rather than fix the bugs bug 109, bug 139!
When Microsoft was questioned about this change on MSDN and the IE Blog Microsoft chose not to comment. In fact Microsoft has been pretty quiet in general since committing to the final RTM builds of Windows 8 (and thus IE10) not responding to any of the direct questions from developers. Read into that what you will, but we find it very unsettling... lack of communication is never a good thing.
Known Workarounds: None.Related Issues: bug 109, bug 139