Random Char Generator (Alpha-Numeric) v2.1

/**
 * PROJECT CLEVERWEB GENERAL LESSER LICENSE INFORMATION v3.1
 * ------------------------------------------------------------
 * Copyright (C) 2011-2012 Nicholas Jordon
 * All rights reserved
 * Package: Project CleverWeb
 * http://ProjectCleverWeb.com
 *
 * License:
 *   GNU LESSER GENERAL PUBLIC LICENSE VERSION 3
 *
 * This software is free software: you can redistribute it
 * and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software
 * Foundation, version 3 of the License, You may not use this
 * software except in compliance with the license.
 *
 * You may obtain a copy of the license at:
 *   http://www.gnu.org/licenses/lgpl-3.0.html
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the license is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.
 *
 * Verfication Key: e450edcbe7703e40d9edcf19a18fb4bc
 */
function cw_randchar($length=NULL,$case=NULL,$spaces=NULL) {
  // Removes "," chars if it is a number
  if(!is_numeric($length)){
    $temp_length = $length;
    if(strstr($length,",")){
      $length = preg_replace("/[,]*/","",$length);
      if(!is_numeric($length)){
        $length = strlen($temp_length);
      }
    }
    elseif(!is_numeric($length)){
      $length = strlen($length);
    }
  }
  if($length==NULL||$length==0){
    // Best password length
    $length = 8;
  }
  // 2000 seems enough?
  if($length>2000){
    $length = 2000;
  }
  // numbers done twice so their % chance stays the same
  $characters = "0123456789abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  $length = ceil($length);
  if(stristr($case,"lower")){
    $characters = "0123456789abcdefghijklmnopqrstuvwxyz";
    $case = true;
  }
  if(stristr($case,"upper")){
    $characters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    $case = true;
  }
  if($spaces==true){
    // 8 spaces to make it seem more like encrypted words
    $characters .= "        ";
    if(!$case==true){
      // 8 more if both capital and lower-case letters
      $characters .= "        ";
    }
  }
  if(!is_bool($spaces)){
    // return error msg
    /**
     * NOTE: the error class, function and/or message is not published
     * in this function but is respectfully included as part of this
     * function as an "intellectual" object under CleverWeb's license.
     */
  }
  // this part is done oddly due to it will otherwise error.
  // it kept being one char place short randomly however not consistantly.
  for ($count = 1; ; $count++) {
    if (strlen($string)==$length) {
      break;
    }
    $string .= $characters[mt_rand(0, strlen($characters))];
  }
  return $string;
}