ajax smart search

Straightforward ajax smart search. I'm going to be collecting mobile numbers and names input as phone book. ? When the user starts typing a phone number, suggestions from the phone book appear underneath the text field. ? Otherwise if the type a name, similarly suggestions pop up to assist the user. I will create the address book - I'm not sure what sort of db is needed on the script side so I'll leave that open to suggestions, coder to provide the mechanism to achieve the above.