regarding dropdowns

Hi all,

I have a problem with dropdowns. I am using dropdown by key. When my screen loads, the dropdown gets filled in by some values from bapi. Now, I have got a requirement that I need to add a null value to the dropdown(i.e., there needs to be a empty value which should allowed for selection along with the values from the BAPI.).

How can I do that? Can I add new values to the dropdown which is populating from a BAPI? And if i can do that, how can add a space(or a null value at the top of the list)

Could anyone please help me regarding this?

Regards,

Murthy.