Sending multiple requests with correct order?

On a toolbar button click, I send three different types of data (two grids, one form) to the server; but the order of hitting server is not the same always:

dataproc_ref_grid.sendData();
dataproc_sub_grid.sendData();
myForm.send(“/Trans/SaveMain”, “post”, function (loader) {

how can I ensure that this batch of requests process in the same order as called?

You can use callbacks to chain data seding

dataproc_ref.attachEvent("onFullSync", function(){ dataproc_sub_grid.sendData(); }); dataproc_ref_grid.sendData();

No it doesn’t seem to be working; now I call dp_ref.sendData(); on click; it calls 1st process well but then gets stuck and does not proceed;i.e. dp_ref.sendData() hits server but dp_sub.sendData(); and as a result myForm.send do not get called:

    dp_ref.attachEvent("onFullSync", function () {
        alert("sending sub now...");
        dp_sub.sendData();

    });

    dp_sub.attachEvent("onFullSync", function () {
        alert("sending form now...");
        myForm.send("/Trans/SaveMain", "post", function (loader) {

//…

        });

    });

Please note that the same chaining works okay with attachEvent(“onAfterUpdate”…but in that case every request is a fresh new request on the server and my in-memory object is re-initialized at every request; what I want to do is:
1- send dp_ref data and store it in an obj.
2- then send dp_sub data and then store it to in obj.
3. finally send myForm data and store it too in obj. And then my DAL persist all data in db.

Using onAfterUpdate loses data stored in step 1 & 2 on each subsequent request. I am using ASP.NET MVC3 and my actionmethods return :

There is no way to send data for multiple components and process them as single operation.