How do I collect List of inputs (unknown nos.)

How do I collect List of inputs (unknown nos.)

I tried to a multi list box to be updated according to the input typed in a text box. In the Entitiy form, I need to collect all the attributes they want to enter.
How can I do it with your application.

Bye the way , why there is no button control?

Thanks.
Moorthi
pvmoorthi.jobs