Blinking while changing brightness of led

1int pin=9;
2int brightness1=5;
3int brightness2=100;
4int brightness3=255;
5int  del=500;
6void setup() {
7  // put your setup code here, to run once:
8pinMode(pin,OUTPUT);
9}
10
11void  loop() {
12  // put your main code here, to run repeatedly:
13analogWrite(pin,brightness1);
14delay(del);
15analogWrite(pin,brightness2);
16delay(del);
17analogWrite(pin,brightness3);
18delay(del);
19}