我在做一个界面，但是在浏览器上显示的时候，最大化是显示正常的，但点击还原按钮的时候，右边的内容自动移到中间位置去了，而原本右边的位置却变空白了。求大神们解答，急急急！！！
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<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Logon.aspx.cs" Inherits="Web.Logon" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"><link rel="stylesheet" type="text/css" href="Styles/Main.css"/> <title>LOGON</title> <style type="text/css"> .sidebar { height: 375px; width: 180px; } </style></head><body id="body"> <form id="form1" runat="server"> <div id="header1"><img alt="Columbia" id="Image" src="images/01.jpg" /></div> <div id="container1"> <div id="mainContent1"> <div id="sidebar1"><img alt="Why" class="sidebar" src="images/cipflyer.jpg" /></div> <div id="sidebar2"> <img alt="Log" src="images/0.jpg" /> <img alt="Log" src="images/131U0G9354140-595A8.png" /> <ul> <li class="li1">UserID:</li> <li class="li2"> <asp:TextBox ID="txtUserID" runat="server"></asp:TextBox> </li> <li class="li1">Password:</li> <li class="li2"><asp:TextBox ID="txtPWD" runat="server"></asp:TextBox> </li> <li class="li3"> <asp:Button ID="btnLogin" runat="server" Text="Login" /> <asp:Button ID="btnCancel" runat="server" Text="Cancel" /> </li> </ul> </div> <div id="content1">Home<div id="Pre"><pre style="height: 461px"> Columbia International Publishing (CIP), located in the US, is a leading organization that delivers high-quality original research to the world.CIP provides a platform for readers, authors, editors, and peer reviewers to promote scientific research. The CIP team consists of professors, scientists, engineers, enterprise founders,business management experts, and talent staff. International support provided to CIP by companies and universities guarantees rapid,barrier-free delivery of research. In order to promote scientific research, CIP is putting forward its own definition of Open Access,which entails a great deal more than “infinite readership,” as Open Access is commonly described. In order to guarantee the complete authority and editorial independency, CIP signs a contract with each voluntary editorial board member. For a better understanding of CIP, please read CIP’s mission, Why Open Access, the unique definition of CIP’s Open Access, 8 reasons to publish on CIP and 6 reasons to work with CIP. All submitted manuscripts are subject to rigorous peer review. Acceptance of a submission is solely based on recommendations by voluntary editors and peer reviewers.If you are interested in being a CIP editor or peer reviewer, please contact us.All papers and books will be published online shortly after their acceptance. </pre></div></div> </div></div> <div id="footer"> <p> Copyright:<a href="#"> Columbia International Publishing LLC. </a>All rights reserved</p> <p> Address: 3610 Buttonwood Dr. Suite 200, Columbia MO 65201 </p> <p> Telephone: 1-573-886-8964 Fax:573-886-8901 Email: uscip@uscip.org</p></div> </form> </body></html>