XTOB Equipament - last sy-ucomm repeating when press enter

Hi friends.

In function group XTOB has a custom screen for aditional data for Equipament master data IE01.

When I press a YYButton on the screen, it's ok.

But, after that, when I press ENTER button, the sy-ucomm given in user command is repeating for YYbuton.

But I need to know the user pressed ENTER instead. right ?

Any idea to solve this ?

best regards.

Glauco