blackberry: onkeyup doesn't catch BACKSPACE

i need to get value of a INPUT of type TEXT in real time. S开发者_开发百科o i assigned to onkeyup of the INPUT to my function, that evaluates the new value.

It works fine on BB (i use 9780/OS6 for tests) except, that BACKSPACE-Key doesn't fire the event.

Here there's an example of code.

may be you have an idea, how to solve it.

Thanks a lot in advance!

Daniel