Xbee

sorry,semicolon error
master:

int pushbutton = 2;

void setup() 
{
Serial.begin(9600); 
pinMode(2, INPUT);
Serial.print("start ");

}
void loop()
{
  digitalRead(pushbutton);
  if(digitalRead(pushbutton) == HIGH)
  {
    Serial.print("D");
  }
}

slave:

int led = 3;


void setup()
{
  Serial.begin(9600);
  pinMode(3,OUTPUT);
  Serial.print("start on slave");
}
void loop()
{
  
if (Serial.available() > 0)
{
  if (Serial.read() == "D")
  {
    digitalWrite(3,HIGH);
  }
else
{
  digitalWrite(3,LOW);
}
}
}