function passGen(charsCount) {
    var result       = '';
    var words        = '0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM';
    var max_position = words.length - 1,
        position,
        i;
    for(i = 0; i < charsCount; ++i) {
        position = Math.floor (Math.random() * max_position);
        result = result + words.substring(position, position + 1);
    }
    return result;
}