which button is calling the function ?

[N93]

consider I have six buttons that do same work so  I write one function  that use for all of them (example : answer question )
but in this function I need to know who call the function, button 1 or button 6  or ...
How can I understand which button call the function ?
I use the 2dtoolkit Basic button



 

[unikronsoftware]

The functions can take an optional tk2dUIItem parameter, which will be the object that triggered it.