The idea is that the onSave handler send an asyncronous request to the
server, where the save operation is performed, then when you receive
the response from server you can do a refresh of the table grid. For
doing all this you need to use Ajax.Request (review this link:
http://api.prototypejs.org/ajax/Ajax/Request/), The data you need to
transfer are the modified rows, so you need to use method
getModifiedRows and finally the refresh method which allows you to
refresh the table grid.