Load tables in correct order when using ASP.NET MasterPages

I am making use of an ASP.NET Masterpage. I have 3 tables as Columns in my Masterpage. The first table load then the second table that contains my "ContentPlaceHolder" and then table 3.

How or what must I do to load table 1 and then table 3 and then lastly the table 2 that contains the "ContentP开发者_开发问答laceHolder"?

try the following senario :

<Style>
#left
{
    float:left;
    width:150px;
    background-color:Black;
}
#right
{
    float:right;
    width:150px;
    background-color:Yellow;
}
#center
{
    margin-left:auto;
    margin-right:auto;
}
</Style>
<div id="left">
    Left Column
    </div>
    <div id="right">
    right Column
    </div>
    <div id="center">
    Content
    </div>