delete sms from sim900

[ehsan8888]

I try with below project to remote control main contactor of a system with sms and receive feedback from main contactor action with below program; I can send sms to sim900 module ;for example when I send sms “MAIN CONTACTOR ON” to sim900 pin output MAIN will be high and sim900 after receive feedback (digitalRead(9)==HIGH) will send sms to mentioned numbers and in the end of viod loop I try to delete all sms from sim card whit: sms.DeleteSMS((int)pos);
But whit start viod loop again pin output MAIN will be high again (the opposite of desire). and because of feedback existence (digitalRead(9)==HIGH) sim900 will send sms to mentioned numbers again (the opposite of desire).
Therefore I will have send sms by sim900 because of feedback existence (digitalRead(9)==HIGH) every cycle (over and over) the opposite of desire .
Please give your proper advice to rectify this problem.

void loop(){
pos=sms.IsSMSPresent(SMS_UNREAD);
Serial.println((int)pos);
if((int)pos>0&&(int)pos<=20){
Serial.print("NUOVO MESSAGGIO, POS=");
Serial.println((int)pos);
message[0]='\0';
sms.GetSMS((int)pos,number,message,180);
}
p=strstr(message,"MAIN CONTACTOR ON");
if(p){
digitalWrite(MAIN,HIGH);
if(digitalRead(9)==HIGH){
if (sms.SendSMS("09137841587", "System on"))
if (sms.SendSMS("09137841712", "System on"))
Serial.println("\nSMS sent OK");
}
}
p=strstr(message," MAIN CONTACTOR OFF");
if(p){
digitalWrite(MAIN,LOW);
if(digitalRead(9)==LOW){
if (sms.SendSMS("09137841587", "System off"))
if (sms.SendSMS("09137841712", "System off"))
Serial.println("\nSMS sent OK");
}
}
sms.DeleteSMS((int)pos);
}