Thankyou Ioannis, i have decided to remove the option for the response from the phone since i think that can only be achieved practically not through simulation, BUT, i have encountered one problem!, When the push button(interrupt) is detected the microcontroller sends a message contineously, how can i stop this?, I want it to send a message only once on detection of an interrupt, my code is below
regards
code:

BEGIN:
if PORTD.2 = 0 then SEND_SMS
GOTO BEGIN

SEND_SMS:
sound PORTB.2,[100,10,50,10]
HIGH PORTB.6
HSEROUT ["at+cmgs=",34,"+256782277658",34,13]
PAUSE 1000
HSEROUT ["An interruption has occured",34,13]
LOW PORTB.6
pause 1000
HIGH PORTB.6
HSEROUT ["at+cmgs=",34,"+256772021358",34,13]
PAUSE 1000
HSEROUT ["An interruption has occured",34,13]
goto BEGIN