read SMS GSM SIM900

can someone tell me what is wrong with this code please, and how can I edit it.

char RcvdMsg[200] ="";
int RcvdCheck = 0;
int RcvdConf = 0;
int index = 0;
int RcvdEnd = 0;
char MsgMob[15];
char MsgTxt[50];
int MsgLength = 0;

void setup()
{
Serial.begin(9600);
Config();
}

void loop()
{
RecSMS();
}

void Config() // This function is configuring our SIM900 module i.e. sending the initial AT commands
{
delay(1000);
Serial.print("ATE0\r");
Response();
Serial.print("AT\r");
Response();
Serial.print("AT+CMGF=1\r");
Response();
Serial.print("AT+CNMI=1,2,0,0,0\r");
Response();
}

void Response() // Get the Response of each AT Command
{
int count = 0;
Serial.println();
while(1)
{
if(Serial.available())
{
char data =Serial.read();
if(data == 'K'){Serial.println("OK");break;}
if(data == 'R'){Serial.println("GSM Not Working");break;}
}
count++;
delay(10);
if(count == 1000){Serial.println("GSM not Found");break;}

}
}

void RecSMS() // Receiving the SMS and extracting the Sender Mobile number & Message Text
{
if(Serial.available())
{
char data = Serial.read();
if(data == '+'){RcvdCheck = 1;}
if((data == 'C') && (RcvdCheck == 1)){RcvdCheck = 2;}
if((data == 'M') && (RcvdCheck == 2)){RcvdCheck = 3;}
if((data == 'T') && (RcvdCheck == 3)){RcvdCheck = 4;}
if(RcvdCheck == 4){RcvdConf = 1; RcvdCheck = 0;}

if(RcvdConf == 1)
{
if(data == '\n'){RcvdEnd++;}
if(RcvdEnd == 3){RcvdEnd = 0;}
RcvdMsg[index] = data;

index++;
if(RcvdEnd == 2){RcvdConf = 0;MsgLength = index-2;index = 0;}
if(RcvdConf == 0)
{
Serial.print("Mobile Number is: ");
for(int x = 4;x <17;x++)
{
MsgMob[x-4] = RcvdMsg[x];
Serial.print(MsgMob[x-4]);
}
Serial.println();
Serial.print("Message Text: ");
for(int x = 46;x <MsgLength;x++)
{
MsgTxt[x-46] = RcvdMsg[x];
Serial.print(MsgTxt[x-46]);
}
Serial.println();
}
}
}
}

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can someone tell me what is wrong with this code please

That's your job. The code, if it compiles, does something. You need to explain what it does.

You expect it to do something. You need to explain what you expect.

Then, we might be able to help you adjust the code or your expectations.