Compare your code to the one below, you should have a page that looks something like this.

• To make the LED flash faster just change the delay from 1000 milliseconds to a shorter time eg. delay (100);  note very short delays eg. 10 milliseconds will appear as if the LED is staying on as the human eye will not notice the on and off phase. 
• To slow the LED flash down simply increase the delay readings to a larger number eg. delay (3000);
• When adding another LED you will need to change the code in several places. Spot the difference in the answer below. 

Making the LED flash alternately requires the high and low states to be opposite for the two LEDs. See the code below for an example of alternating LED flashes.