php mysql 分页函数

+-----------------------------------------------------------------------
| 文件概要：分页显示函数
| 文件名称：page.php
| 创建时间：2010-5-20
+-----------------------------------------------------------------------
*/
 function _pageft($totle, $displaypg = 20, $url = '') {

  global $page, $firstcount, $pagenav, $_server;

  $globals["displaypg"] = $displaypg;

  if (!$page)
   $page = 1;
  if (!$url) {
   $url = $_server["request_uri"];
  }

  //url分析：
  $parse_url = parse_url($url);
  $url_query = $parse_url["query"]; //单独取出url的查询字串
  if ($url_query) {
   $url_query = preg_replace("/(^|&)page=$page/", "", $url_query);
   $url = str_replace($parse_url["query"], $url_query, $url);
   if ($url_query)
    $url .= "&page";
   else
    $url .= "page";
  } else {
   $url .= "?page";
  }
  $lastpg = ceil($totle / $displaypg); //最后页，也是总页数
  $page = min($lastpg, $page);
  $prepg = $page -1; //上一页
  $nextpg = ($page == $lastpg ? 0 : $page +1); //下一页
  $firstcount = ($page -1) * $displaypg;

  //开始分页导航条代码：
  $pagenav = "显示第 " . ($totle ? ($firstcount +1) : 0) . "-" . min($firstcount + $displaypg, $totle) . " 条记录  共 $totle 条留言";

  //如果只有一页则跳出函数：
  if ($lastpg <= 1)
   return false;

  $pagenav .= " 首页 ";
  if ($prepg)
   $pagenav .= " 前页 ";
  else
   $pagenav .= " 前页 ";
  if ($nextpg)
   $pagenav .= " 后页 ";
  else
   $pagenav .= " 后页 ";
  $pagenav .= " 尾页 ";

  //下拉跳转列表，循环列出所有页码：
  $pagenav .= "　到第 n";
  for ($i = 1; $i <= $lastpg; $i++) {
   if ($i == $page)
    $pagenav .= "$in";
   else
    $pagenav .= "$in";
  }
  $pagenav .= " 页   共 $lastpg 页";
 }
?>