[jQuery] refresh a DIV

I have a DIV with a php query in it. i'd like to get pointers to
maybe 2 solutions.
Ideal situation:
I have a other jquery script that launches an onComplete like:
'onComplete': { }
basicly i want to let it do a refresh on <div id='records'> #My sql
query# </div>
other situation
I want to refresh this DIV every 5 seconds.
Can someone help me pleaaaase!
D.