How to make combobox values searchable character by character (google like)?

Hi,

I was wondering how to make combobox values searchable character by character (google like). For example, if text box cointains list of emploleey (their names), if I type 'J' I will get automatic generated list of names starting with J. If I type 'Ja' I will get autmatic list of names like, Jack, James, Jason...

Any help is appreciated and many thanks in advance.
Adi