Control water pump through sms using a old sony phone interfaced with arduino

I want to compare the received message with string "ON" and "OFF"
and if the message contains ON then set a digital pin high for 30 minutes max and
if OFF is received then set that digital pin Low.

void setup() {

Serial.begin(9600);
delay(3000);
Serial.println("AT+CPMS="ME""); // AT commands for sony T610
delay(3000);
Serial.println("ATE=0"); // ECHO off
delay(3000);
Serial.println("AT+CMGF=1"); //text format
delay(3000);
Serial.println("AT+CMGR=1"); //read text message from the location 1 of the phone
delay(3000);

if (Serial.available() > 0) {
/* Now i cant understand how to assign that
data string received in the form of text message to a memory
locaton on arduino and compare with another string and
then do the appropriate action.*/

/* I want to compare the received message with string "ON" and "OFF"
and if the message contains ON then set a digital pin high for 30 minutes max and
if off is received then set that digital pin Low

*/
}

void loop() {

}

PLEASE HELP ME I GOT STUCK...

testing.pde (869 Bytes)

How about using NewSoftSerial to interface to the phone and then the normal Serial library can be used to debug via USB so you can see what's coming from the phone?