[Vince]

That gets the decimal though, not the character code which he's after. I suggest you add these little wrappers first:

PHP код:

minrandom(min, max)
    return random(max - min) + min;

isOdd(number)
    return number & 1; // faster than mod 


Then you can easily use these wherever they are needed.

PHP код:

iKey[i] = isOdd(i) ? minrandom('1', '9') : minrandom('a', 'z');