Need help converting String to int...

I have another issue now... I am trying to add some error checking to the if statement in the loop() function.
The if statement tests for index to be greater than 4 or inByte to be either a charage return or line feed.
I need to clear inData and break the while loop if index is less than 5, but a charage return/line feed was received.

I have tried several things, but none seem to achieve the intended results. Any ideas?

void loop() {   
  while (Serial.available() > 0){
    inByte = Serial.read ();          //read serial input one byte at a time
    inData[index] = inByte;           //add serial input to array
    index++;                          //increment index (length/bytes of serial data received)
    if (index > 4 || inByte == 10 || inByte == 13){  //serial data is 5 bytes longs or received a charage return or line feed
      if (index < 5){
            //clear inData...
            break;
      }
      inData[index] = '\0';           //Null terminate the string
      index = 0;                      //reset index
      unsigned long tmp = atoi(inData);
      servo_num = tmp / 1000;
      servo_pos = tmp % 1000;
      if (servo_pos > 180){
        servo_pos = 180; 
      }
      Serial.println(servo_num);
      Serial.println(servo_pos);
    }
  }   
}