php mysql 分頁函數

+-----------------------------------------------------------------------
| 檔案概要：分頁顯示函數
| 檔案名稱：page.php
| 建立時間：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 = $parse_url["query"]; //單獨取出url的查詢字串
  if ($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); //最後頁，也是總頁數
  $page = min($lastpg, $page);
  $prepg = $page -1; //上一頁
  $nextpg = ($page == $lastpg ? 0 : $page +1); //下一頁
  $firstcount = ($page -1) * $displaypg;

  //開始分頁導航條代碼：
  $pagenav = "顯示第 <b>" . ($totle ? ($firstcount +1) : 0) . "</b>-<b>" . min($firstcount + $displaypg, $totle) . "</b> 條記錄&nbsp;&nbsp;共 <font color='red'>$totle</font> 條留言";

  //如果只有一頁則跳出函數：
  if ($lastpg <= 1)
   return false;

  $pagenav .= " <a href='$url=1'>首頁</a> ";
  if ($prepg)
   $pagenav .= " <a href='$url=$prepg'>前頁</a> ";
  else
   $pagenav .= " 前頁 ";
  if ($nextpg)
   $pagenav .= " <a href='$url=$nextpg'>後頁</a> ";
  else
   $pagenav .= " 後頁 ";
  $pagenav .= " <a href='$url=$lastpg'>尾頁</a> ";

  //下拉捷徑清單，迴圈列出所有頁碼：
  $pagenav .= "　到第 <select class='border:1px solid #98ccfa;' name='topage' size='1' onchange='window.location="$url="+this.value'>n";
  for ($i = 1; $i <= $lastpg; $i++) {
   if ($i == $page)
    $pagenav .= "<option value='$i' selected>$i</option>n";
   else
    $pagenav .= "<option value='$i'>$i</option>n";
  }
  $pagenav .= "</select> 頁&nbsp;&nbsp;&nbsp;共 <font color='red'>$lastpg</font> 頁";
 }
?>