InfoPath Dev

Scenario:
I have a Trusted Form in a form library with datafields and
a signature button. I need the next functionality in the button code:
a) set a field a value=1
b) Sign the form
c) save data to my main Connection and send the form to the form library.

I write this, but ip send me a error message:

function XDocument::OnSign(eventObj)
{
var Signature = eventObj.SignedDataBlock.Signatures.Create();
XDocument.DOM.selectSingleNode("/dfs:myFields/dfs:dataFields/d:SolicitudesMS/@autorizado").text="1"

Signature.Sign();
eventObj.ReturnStatus = true;

var oXDocument= XDocument.DataAdapters("MainCnx");
oXDocument.Submit();
var oXDocument2= XDocument.DataAdapters("SendSharePoint");
oXDocument2.Submit();
}


It is posible to do this???

It would be helpful if you provided us with the error message that you are seeing.

ok, i try to translate the error message:
-------------------
InfoPath can´t send the form.
Error sending the form.
Error after send succesfully the changes to data source.

Must save and close the form before continue
This value has been signed digitally and can not be changed.
--------------------
InfoPath can´t send the form
[Microsoft Cursor engine] Can not find the row for update: some values has changed from the last time read it.
------------------

I am using digital signature for a section.
Can i update a field and then save to database after i did sign a form.
Note: my field not is part of the signed section.