function string_generator(nb_caract) {
var chaine = Array('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','0','1','2','3','4','5','6','7','8','9');
var pass = '';
var nb, u;
for (u=1; u <= nb_caract; u++) {
nb = chaine.length;
nb = Math.round(Math.random()*chaine.length);
pass += chaine[nb];
}
return pass;
}