Javascript - Callback Function With Parameters

I'm using AJAX Page Methods, but I can't seem to be able to pass the needed parameters:

function getFavStatus() {
//favs is a list of DOM <imgs> that I want to modify their img.src attribute
for (i = 0; i < favs.length; i++) {
PageMethods.isFavorite(favs[i].alt,setFavImg(favs[i]));
}
}
function setFavImg(fav, response) {
fav.src = response;
}
The problem that I can't figure out is how to use the "response" from PageMethods, AND pass the DOM object to the callback function.
I've also tried doing something like this:
function getFavStatus() {
for (i = 0; i < favs.length; i++) {
PageMethods.isFavorite(favs[i].alt, function (response) {
favs[i].src = response;});
);
}
}

In this case, the response works properly, but i is always > favs.length, because it has already iterated through the loop... Edit: My PageMethods.isFavorite signature is: [System.Web.Services.WebMethod] public static string isFavorite ( string p_id )