BAPI Usage button event did not trigerred

Hi Dear All,

I get through the Tutorial 2 BAPI Usage. I think most of you know that course. Here I encounter an issue that when I press the button 'Search Flight', nothing get. Then in the Event Handler ONACTIONGET_FLIGHTS, I write the code 'BREAK-POINT'. But it did not go into debug mode. Could anyone give me any hints. I just go through the PDF as what it said.   Thank you sooooo much.

Regards

Jay