Big challenge Autocomplete

[virgul]

Hi,

I wan't to know if it's possible to do a things like that:

I have a Dropdown listebox and with a item (do in C# an add new if you
wan't) I wan't that when the user write somethings in example pre
infopath autocomplete president. This entry is already in the listebox
but I wan't that if the user want enter the name of function
(président,secretary,..) infopath make an autocomplete based on the
field in the dropdown listebox(send by a webservice).

Do you think it's possible? Have any idea about how to do?

Thanks for any suggest

++

Thierry