Modifying APN settings in embedded linux

Below ppp-on-dialer script has to be modified to change the APN settings.

Field after "IP" is the APN settings. In the below example AP is airtelgprs.com

#!/bin/sh
#
# This is part 2 of the ppp-on script. It will perform the connection
# protocol for the desired connection.
#
exec chat -v      \
 TIMEOUT  10    \
 ABORT  '\nBUSY\r'   \
 ABORT  '\nNO ANSWER\r'   \
 ''  'ATZ'    \
 'OK'  'ATQ0 V1 E1 S0=0 &C1 &D2' \
 'OK'  'AT+CGDCONT=1,"IP","airtelgprs.com"' \
 'OK'  'ATDT*99***1#'   \
 CONNECT  ''