Infotype: How to know witch button was pressed?

Hi.

I have a new infotype 9xxxx, and i would like to know wich buttom was pressed in the first screen of transaction pa30, in order to know if i have to presentate the dympro in visualitation mode or modification mode... i tried with the sy-ucomm but when the infotype 9xxx begins the value of sy-ucomm it's initial.

Also... how could i determine if the action was taken in pa20 or pa30?

Thanks!

Albio.-