I can know if an incoming sms is reply of an sent sms???

Hi everyone...

As the title suggests, need to know if an incoming message is in response to one sent, I'll explain:

If a phone [[B]A[/B]] sends an SMS [[B]X[/B]] to a phone [[B]B[/B]], to open the message [B]X[/B] in [B]B[/B] creates a message [SMS [B]Y[/B]] as response to the SMS [B]X[/B] and that is sent to [B]A[/B].

In the phone [B]A[/B] to receive the SMS [B]Y[/B], how I can know that SMS is in response to [B]X[/B]?

Is there any way of knowing?

SMS is not email, which has In-Reply-To: field allowing following message threads. You can know only sender.