display real time addition as we type number

Hi,

Is it possible to display real time addition, as we enter number in input field.  Say for example, I have three input fields: IP1, IP2 and IP3.

Now as I enter value in IP1 - Type the number, at the same moment IP3 should display sum of IP1 and IP2. 

IP2 = 10

IP1 = Typed 1 -->  IP3 = 11 

IP1 = Typed 12 --> IP3 = 22

We are not pressing enter or any button.

Is this possible in webdynpro abap, by any means (other ui element).

Thanks,

Sumeet