Write Javascript code which gets executed when that button gets pressed. It should generate a random string of n characters (n is a parameter) where characters are potentially uppercase and lowercase letters and the ten digits. How to generate random char/digit: choose a random number r between 0 and 127; if it is in range 48-57 (digits), or 65-90 (uppercase letters), or 97-122 (lowercase letters) then return chr(r); otherwise try again until you get an acceptable character. (You can also narrow down the range to improve likelihood of a good character.) Repeat this n times to get n chars for shortened string.