Select, Deselect wont display selection in Table control of MP program

Hi Experts,

I have developed a module pool program, where in i have created buttons Select All and Deselect All in GUI status just like standard ones.

So my requirement is to either select all records or deselect all records displayed in the table control. But I am not able to achieve this simple functionality and i am not sure where i missing something. Whats interesting is, the internal table that's displayed in Table control, in debug mode, marks X for those records, but just wont display on the screen after execution. So for sure i am missing something, so can you please help me with this.

Thank you,

CB