Help me with taxonomy field

Hi,

i'm declaring a taxonomy say C1 with pre-defined entrys A,B and C and free-tagging is enabled.
On the form appears the taxonomy field and user can input some new terms or select from list.

But the list only appears if you type at least one character in the field.

Is there a way that the list appears on entering the field or do a click in the empty field ?

Thank you, Peter.