脚本代码：

// GT.ru pic preview script
// version 0.1
// 2011-6-26
// Copyright 2011, dangl71
// Released under the GPL license
// hxxp://www.gnu.org/copyleft/gpl.html
//
// --------------------------------------------------------------------
//
// This is a Greasemonkey user script.  To install it, you need
// Greasemonkey 0.3 or later: hxxp://greasemonkey.mozdev.org/
// Then restart Firefox and revisit this script.
// Under Tools, there will be a new menu item to "Install User Script".
// Accept the default configuration and install.
//
// To uninstall, go to Tools/Manage User Scripts,
// select "GT.ru", and click Uninstall.
//
// --------------------------------------------------------------------
//
// ==UserScript==
// @name          GT.ru
// @description   change GT.ru pic preview
// @include       http://tracker.gaytor.rent/details.php*
// ==/UserScript==

picDiv = document.createElement("div");
picDiv.setAttribute("id", "picDiv");
picDiv.setAttribute("style", "position:absolute; top:100px; left:0px; z-index:99; visibility:hidden; width:99.6%; height:80%; text-align:center");
picDiv.innerHTML = '<iframe id="theFrame" border="0" style="width:100%; height:95%; background:gray" noresize="resize"></iframe>
  >> Close Pic Preview <<  ';
document.body.appendChild(picDiv);

newScript = document.createElement("script");
newScript.innerHTML = 'function showpic(pic) { document.getElementById("theFrame").src="/showpic.php?pic=" + pic; document.getElementById("picDiv").style.visibility="visible"; document.getElementById("picDiv").style.top = window.pageYOffset + "px"; } function hidePic() { document.getElementById("picDiv").style.visibility="hidden"; }';
document.body.appendChild(newScript);

newScript = document.createElement("script");
newScript.innerHTML = 'window.onscroll = function () { document.getElementById("picDiv").style.top = window.pageYOffset + "px" }';
document.body.appendChild(newScript);

function scrollpicDiv(){ document.getElementById("picDiv").style.posTop = document.body.scrollTop; }

以上脚本。

首先要安装greasemonkey插件（重启FF以后才可以应用）。把这段代码复制下来，存成 yourfilename.user.js 文件，把它拖进FF窗口，应该就可以了。

@管理员/版主：
@include那一句链接的是本站URL，不要改成hxxp哦！