php 获取用户ip与ie信息程序
function onlineip()
 {
  global $_server;
  if(getenv('http_client_ip'))
  {
   $onlineip = getenv('http_client_ip');
  }
  elseif(getenv('http_x_forwarded_for'))
  {
   list($onlineip) = explode(',', getenv('http_x_forwarded_for'));
  }
  elseif(getenv('remote_addr'))
  {
   $onlineip = getenv('remote_addr');
  }
  else
  {
   $onlineip = $_server['remote_addr'];
  }
  return $onlineip;
 }
 function imgdecode($string)
 {
  global $_server;
  $key = md5(onlineip().\t.$_server['http_user_agent']);
  $coded = '';
  $string = base64_decode($string);
  $keylength = strlen($key);
  for($i = 0; $i   {
   $coded .= substr($string, $i, $keylength) ^ $key;
  }
  return $coded;
 }