[TYPO3-templavoila] Limit the width of the TV layout in BE

[Christian Leicht]

Hello i tried to limit the overall width of the pagelayout in BE.
I use in my templatefile in BE:

<table width="700" border="0" cellspacing="0" cellpadding="0">
   <tr>
     <td>###field_teaser2###</td>
   </tr>
   <tr>
     <td>###field_inhalt###</td>
   </tr>
   <tr>
     <td>###field_grosser_footer###</td>
   </tr>
</table>

But in BE the width is 1400px, without content who is blow it up.
I have a lot of empty space.

How can i limit it
Thanks for Help

Christian