cms columns

[dang3rzon3]

Good morning, i have a question related to a modify that I want to do in the layout of my vbullettin portal.
I want to divide in a personalized way the width of my three columns where i had put my widgets.
Going in the menu "GRID" and selecting the grid that i want to modify, i select the point of the existent code for the flat format grid and I modify the code in this way:
- Nascondi testo citato -

<div id="doc3">
<div id="hd" >
<div class="yui-u yui-header">
<ul class="list_no_decoration widget_list" id="widgetlist_column1">$column[1]</ul>
</div>
</div>
<div id="bd" >
<div class="yui-g">
<div class="yui-tvb-l25 first yui-panel" width="120px">
<ul class="list_no_decoration widget_list" id="widgetlist_column2">$column[2]</ul>
</div>
<div width="560px" class="yui-tvb-l50 first yui-panel">
<ul class="list_no_decoration widget_list" id="widgetlist_column3" >$column[3]</ul>
</div>
<div class="yui-tvb-l25 first yui-panel" width="140px">
<ul class="list_no_decoration widget_list" id="widgetlist_column4" >$column[4]</ul>
</div>
</div>
</div>
<div id="ft" >
<div class="yui-u yui-footer">
<ul class="list_no_decoration widget_list" id="widgetlist_column5">$column[5]</ul>
</div>
</div>
</div>

With this code I added the personalized width in the tag DIV of each column.
The result it isn't like should be, beacuse the final layout is not modified.
Please, can you give me some instructions to reach the expected result?