if($_GET['len'] != "" && $_GET['len'] >= "3") {
    $uzunluk = $_GET['len']; }

else {
    $uzunluk = "6"; }

function generatePassword($length=6,$level=2){

   list($usec, $sec) = explode(' ', microtime());
   srand((float) $sec + ((float) $usec * 100000));

   $validchars[1] = "0123456789abcdfghjkmnpqrstvwxyz";
   $validchars[2] = "0123456789abcdfghjkmnpqrstvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
   $validchars[3] = "0123456789_!@#$%&*()-=+/abcdfghjkmnpqrstvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_!@#$%&*()-=+/";

   $password  = "";
   $counter   = 0;

   while ($counter < $length) {
     $actChar = substr($validchars[$level], rand(0, strlen($validchars[$level])-1), 1);

     // All character must be different
     if (!strstr($password, $actChar)) {
        $password .= $actChar;
        $counter++;
     }
   }

   return $password;
}


echo '
<div class="container">
<div class="box">
<fieldset>
<legend><img src="images/1.png"></legend>
<input class="pass" type="text" value="'.generatePassword($uzunluk,"1").'" onclick="select();" /> <br />
<input class="pass" type="text" value="'.generatePassword($uzunluk,"1").'" onclick="select();" /> <br />
<input class="pass" type="text" value="'.generatePassword($uzunluk,"1").'" onclick="select();" /> <br />
</fieldset>
</div>

<div class="box">
<fieldset>
<legend><img src="images/2.png"></legend>
<input class="pass" type="text" value="'.generatePassword($uzunluk,"2").'" onclick="select();" /> <br />
<input class="pass" type="text" value="'.generatePassword($uzunluk,"2").'" onclick="select();" /> <br />
<input class="pass" type="text" value="'.generatePassword($uzunluk,"2").'" onclick="select();" /> <br />
</fieldset>
</div>

<div class="box">
<fieldset>
<legend><img src="images/3.png"></legend>
<input class="pass" type="text" value="'.generatePassword($uzunluk,"3").'" onclick="select();" /> <br />
<input class="pass" type="text" value="'.generatePassword($uzunluk,"3").'" onclick="select();" /> <br />
<input class="pass" type="text" value="'.generatePassword($uzunluk,"3").'" onclick="select();" /> <br />
</fieldset>
</div>

<div style="clear:both; margin-bottom: 20px"></div>

<form name="sifre" action="'.$PHP_SELF.'" method="GET">
<b>Yeni şifre oluştur</b><br />
Uzunluk:
<select name="len" onchange="document.sifre.submit();">';

for($i=3; $i<=15; $i++) {
    echo '<option'; if($uzunluk == "$i") { echo ' selected'; } echo '>'.$i.'</option>';
}

    echo '</select>
    <input type="submit" value="Yeni" style="cursor:pointer" />
</form>
</div>';