The passwords generating procedure is placed under the timer1_Timer () event so that the procedure is repeated after every interval. The interval of the timer can be set in its properties window where a value of 1 is equivalent to 1 millisecond. Therefore a value of 1000 is equivalent to 1 second; the smaller the value, the shorter the interval. The Timer1.Enabled property is set to false so that the program will only start generating the passwords after you click on the command button. Rnd is a VB function that generates a random number between 0 and 1. Multiplying Rnd by 100 will obtain a number between 0 and 100. Int is a VB function that returns an integer by ignoring the decimal part of that number.