Forum Post: no output

when i upload this program to blink led iam  not able to see any out board i dont know whats wrong with this can any one help me? #include Arduino.h // the setup function runs once when you press reset or power the board void setup() {   // initialize digital pin 13 as an output.   pinMode(13, OUTPUT); } // the loop function runs over and over again forever void loop() {   digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)   delay(1000);              // wait for a second   digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW   delay(1000);              // wait for a second }