Temporary password in PHP

function randompassword($len)
{
$pass = '';
$lchar = 0;
$char = 0;
for($i = 0; $i < $len; $i++)
{
    while($char == $lchar)
    {
     $char = rand(48, 109);
     if($char > 57) $char += 7;
     if($char > 90) $char += 6;
    }
    $pass .= chr($char);
    $lchar = $char;
}
return $pass;
}