Servo control on serial monitor

Projects Programming
3

#include <Servo.h>
Servo myservo;
int pos = 0;
int a=0;
int incomingByte=0;
void setup()
{
myservo.attach(9);
Serial.begin(9600);
Serial.print("ready ");
}

void loop()
{ if (Serial.available() > 0)
{ incomingByte = Serial.read();
Serial.print((char)incomingByte);
a=1;

if(a==1)
{
for(pos = 0; pos <= 90; pos += 1) 
{                              
  myservo.write(pos);      
  delay(40);                    
} 
delay(3000);
for(pos = 90; pos>=0; pos -=1)     
{                                
  myservo.write(pos);              
  delay(40);                   
}
}

}
}