Below is some code to get you started on creating your own Sharepoint Application Page so that it looks just like the built in ones!
<%@ Assembly Name=”Microsoft.SharePoint, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c”%>
<%@ Assembly Name=”CheckInAll, Version=1.0.0.0, Culture=neutral, PublicKeyToken=70b886b56e89f448″Â %>
<%@ Page Language=”VB” MasterPageFile=”~/_layouts/application.master” Inherits=”VSeWSS.CheckInAll.CheckIn” %>
<asp:Content ID=”PageTitle” contentplaceholderid=”PlaceHolderPageTitle” runat=”server”>
 Check-In: All Documents
</asp:Content>
<asp:Content ID=”PageTitleInTitleArea” runat=”server”
            contentplaceholderid=”PlaceHolderPageTitleInTitleArea” >
 Check-In: All Documents
</asp:Content>
<asp:Content ID=”Main” contentplaceholderid=”PlaceHolderMain” runat=”server”>
<table>
<tr>
 <td class=”ms-descriptiontext” valign=”top”>
    <table border=”0″ cellpadding=”1″ cellspacing=”0″ width=”100%”>
     <tr>
      <td class=”ms-sectionheader” style=”padding-top: 4px;” height=”22″ valign=”top”>
       <H3 class=”ms-standardheader”>
                               Check-In Document
        </H3>
      </td>
     </tr>
     <tr>
      <td class=”ms-descriptiontext ms-inputformdescription”>
      �
                  Add comments to all the documents you are checking in
 �
      </td>
      <td><IMG SRC=”/_layouts/images/blank.gif” width=8 height=1 alt=”"></td>
     </tr>
     <tr>
      <td><IMG SRC=”/_layouts/images/blank.gif” width=150 height=19 alt=”"></td>
     </tr>
    </table>
   </td>
   <td class=”ms-authoringcontrols ms-inputformcontrols” valign=”top”
   align=”left” >
    <table border=”0″ width=”100%” cellspacing=”0″ cellpadding=”0″>
     <tr>
      <td width=”9px”><IMG SRC=”/_layouts/images/blank.gif” width=9 height=7 alt=”"></td>
      <td><IMG SRC=”/_layouts/images/blank.gif” width=150 height=7 alt=”"></td>
      <td width=”10px”><IMG SRC=”/_layouts/images/blank.gif” width=10 height=1 alt=”"></td>
     </tr>
     <tr>
      <td />
      <td class=”ms-authoringcontrols”>
       <table class=”ms-authoringcontrols” border=”0″ width=”100%” cellspacing=”0″ cellpadding=”0″>
       �
  �
     <tr id=”ctl00_PlaceHolderMain_ctl01_ctl02_tablerow1″>
      <td class=”ms-authoringcontrols” colspan=”2″ nowrap>
       <label for=”ctl00_PlaceHolderMain_ctl01_ctl02_InputFile” id=”ctl00_PlaceHolderMain_ctl01_ctl02_LiteralLabelText”>Comments:</label>
      </td>
     </tr>
     <tr id=”ctl00_PlaceHolderMain_ctl01_ctl02_tablerow2″>
      <td><IMG SRC=”/_layouts/images/blank.gif” width=1 height=3 alt=”"></td>
     </tr>
     <!– End Right_Text –>
     <tr id=”ctl00_PlaceHolderMain_ctl01_ctl02_tablerow3″>
      <td width=”11″ ><IMG SRC=”/_layouts/images/blank.gif” width=11 height=1 alt=”"></td>
      <td class=”ms-authoringcontrols” width=”99%”>
      �
                     <TABLE class=”ms-authoringcontrols” width=”100%”>
                   <TR><TD>
                     <SPAN dir=”ltr”>
                     <asp:TextBox runat=”server” Width=”350px” ID=”txtComments” TextMode=”MultiLine” Rows=”5″></asp:TextBox>
                     </SPAN>
                   </TD></TR>
                   </TABLE>
  �
      </td>
     </tr>
    �
     <tr id=”ctl00_PlaceHolderMain_ctl01_ctl02_tablerow5″>
      <td><IMG SRC=”/_layouts/images/blank.gif” width=1 height=6 alt=”"></td>
     </tr>
       </table>
      </td>
      <td width=”10px”><IMG SRC=”/_layouts/images/blank.gif” width=10 height=1 alt=”"></td>
     </tr>
     <tr>
      <td />
      <td><IMG SRC=”/_layouts/images/blank.gif” width=150 height=13 alt=”"></td>
      <td />
     </tr>
    </table>
   </td>
  </tr>
�
  <tr>
   <td height=”2px” class=”ms-sectionline” colspan=”2″>
   <IMG SRC=”/_layouts/images/blank.gif” width=1 height=1 alt=”">
   </td>
  </tr>
 �
  <tr>
   <td height=”10px” class=”ms-descriptiontext” colspan=”2″>
   <IMG SRC=”/_layouts/images/blank.gif” width=1 height=10 alt=”">
   </td>
  </tr>
  <tr>
   <td colspan=”2″>
    <table cellpadding=”0″ cellspacing=”0″ width=”100%”>
     <colgroup>
      <col width=”99%”>
      <col width=”1%”>
     </colgroup>
     <tr>
      <td>
        </td>
      <td nowrap>
       <asp:Button ID=”btnOK” Text=”OK” Width=”100px” runat=”server” />
       <asp:Button ID=”btnCancel” OnClientClick =”window.location=history.back();” Width=”100px” Text=”Cancel” runat=”server” />
      </td>
     </tr>
    </table>
   </td>
  </tr>
 �
  <tr>
   <td height=”40″ class=”ms-descriptiontext” colspan=”2″>
   <IMG SRC=”/_layouts/images/blank.gif” width=1 height=4 alt=”">
   </td>�
    </tr>
   �
 </td>
 </table>
</asp:Content>