http://stackoverflow.com/questions/3883543/javascript-different-keycodes-on-different-browsers 

I was going to bring this up to you but I totally forgot to mention.  It seems that we can't really use keycode if supporting all browsers or OSs is the goal.  And interestingly, JS recommended way of converting keycode to character,  `String.fromCharCode(event.keyCode);` also returns inconsistent result.  

In my setting, OS X with Chrome, Opera and Safari, "/" result in 191 charcode.  When I do `String.fromCharCode(191);` I do not get "/" and I think I have gotten "(" instead.  I was afraid that M$ setting would throw out different charcode.  and I'm unable to convert charcode to character to validate the last entered character.

Since now I know this is true, I think I would have to get the input box text and substring last character to get the true last character value.