Topic: Tamper xajax data

Hi,

I don't know if this is the right place to post my question, my apologies and i hope to be direct to the right place.

I am trying to secure my application against STRIDE, which includes tampering data but it seems to me that xajax has some built in mechanism to prevent it, because whenever i alter some xargs it always gives me the same error: "Error: the XML response that was returned from the server is invalid.
Received: "

This is really good only that i would like to personalize my own message when it happens and not show that kind of messages...

So i would like to confirm:

Does xajax to an extent prevents Tampering attacks and if so how can i personalize the error messages???

Thank you very much.

Luis