表格宽度问题,请高手帮忙
<table border="0" cellspacing="0" cellpadding="0">
                   <thead>
                     <tr>
                       <td width="20"> </td>
                       <td width="60"> </td>
                       <td> </td>
                       <td> </td>
                     </tr>
                   </thead>
                   <tbody>
                     <tr>
                       <td> </td>
                       <td> </td>
                       <td> </td>
                       <td> </td>
                     </tr>
                     <tr>
                       <td colspan="4" valign="top"><table width="100%" border="0" cellspacing="0" cellpadding="0" style="display:none;" id="t1">
   <tr>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
   </tr>
   <tr>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
   </tr>
   <tr>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
     <td> </td>
   </tr>
</table>
</td>
                     </tr>
                   </tbody>
                 </table>
当id="t1"的表格显示的列数大于外部table列数时,外部table宽度等于20的td的宽度会变宽,请问如何解决!
急急急!
------解决方案--------------------
table的宽度和高度会随着里面的子容器撑开,overlfow:hidden;都不管用,如果想要在td里面限制宽度,在里面加一个div,在套table
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
  <head>
 <title> New Document </title>
 <meta name="Generator" content="EditPlus">
 <meta name="Author" content="">
 <meta name="Keywords" content="">
 <meta name="Description" content="">
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  </head>
  <body bgcolor="yellow">
 <table border="0" cellspacing="0" cellpadding="0">
 <thead>
 <tr>
 <td width="20"> </td>
 <td width="60"> </td>
 <td> </td>
 <td> </td>
 </tr>
 </thead>
 <tbody>
 <tr>
 <td> </td>
 <td> </td>
 <td> </td>
 <td> </td>
 </tr>
 <tr>
 <td colspan="4" valign="top"&g