var chars = ['Q','W','E','R','T','Y','U','I','O','P','A','S','D','F','G','H','J','K','L','Z','X','C','V','B','N','M','1','2','3','4','5','6','7','8','9','0'];
var key = "";

for(i = 0; i < 4; i++) {
    key += chars[Math.floor(Math.random() * (chars.length - 0))];
}
key += "-";

for(i = 0; i < 4; i++) {
    key += chars[Math.floor(Math.random() * (chars.length - 0))];
}
key += "-";

for(i = 0; i < 4; i++) {
    key += chars[Math.floor(Math.random() * (chars.length - 0))];
}
key += "-";

for(i = 0; i < 4; i++) {
    key += chars[Math.floor(Math.random() * (chars.length - 0))];
}