Change Power Level Xbee (series1)

I did the modiications on the code:

char str[5] = "OK";

void setup ()
{
  Serial.begin(9600);
  
  Serial.print("+++");
  delay(3000);
  if((int)Serial.read()==(int)str){
  Serial.println("ATPL");
  delay(1000);
  if(Serial.read()>=3){
  Serial.println("ATPL 2");
  delay(1000);
  Serial.println("ATPL");
  }
  }
}

void loop ()
{
 
  
}

Still... Not working =/