SubGrid Referesh and grid Event

Hi All, 

i'm sorry, but i am new to CRM... could you please help me in this :

i have this script that for subgrid

function AddEventToGridRefresh(gridName, functionToCall) {
// retrieve the subgrid
var grid = document.getElementById(gridName);
// if the subgrid still not available we try again after 1 second
if (grid == null) {
setTimeout(function () { AddEventToGridRefresh(gridName, functionToCall); }, 1000);
return;
}
// add the function to the onRefresh event
grid.control.add_onRefresh(functionToCall);
} 

First: is this way supported ? 

Second: i need a supported way for functionToCall, that calls a webservice by sending values from the grid itself, this webservice returns VALUES, these values must be updated in that grid 

Thanks