Hello All,
I am having some problems with creating a 1 column fluid width web page which has a header section and left and right side bars. I can not get it to center nor to display consistently on different browsers. In fact its a complete mess. Please take a look at my attached CSS and HTML file and help point out to me my mistakes. Thank you in advance for your help.

I'm not sure what you want to create, but maybe this will help:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

   <title>My Trials</title>
   <style type="text/css">

      * {margin:0; padding:0;}
      #Header {height:160px; width:100%; background:#df7401;}
      #Container {width:100%; background:#ffffff;}
      #LeftCol, #RightCol {width:5%; background:#000000; height:600px;}
      #LeftCol {float:left;}
      #RightCol {float:right;}
      #Main {height:600px;}
      #Footer {clear:both; height:40px; background:#000000; width:100%;}
      #Nav {padding-top:15px; margin-left:20%;}
      #MiddleCol {float:left; width:90%;}

      #Nav li {list-style-type: none; display:inline;}
      #Nav a, #Nav a:visited {border-top:solid white 1px; border-bottom:solid white 1px; 
                              color:White; font-family:arial, verdana, sans-serif; 
                              font-size:50%; text-align:center; text-decoration:none;
                              padding:1% ; background:gray;}
      #Nav a:hover {background:black; color:white;} 


   <div id="Container">

      <div id="LeftCol">

      </div> <!-- end LeftCol -->

      <div id="RightCol">
      </div> <!-- end RightCol -->

      <div id="MiddleCol">

         <div id="Header">
            <img src="MyImageFile.jpg" alt=""/>

            <div id="Nav">
                  <li><a href="index.html">Home</a></li>
                  <li><a href="Stuff.html">Stuff</a></li>
                  <li><a href="MoreStuff.html">More Stuffs</a></li>
                  <li><a href="About.html">About Us</a></li>
                  <li><a href="Contact.html">Contact Us</a></li>

            </div> <!-- end Nav -->
         </div> <!-- end Header -->

      </div> <!-- end MiddleCol -->

      <div id="Footer">
      </div> <!-- end Footer -->

   </div> <!-- end Container -->

At least it looks the same in Firefox 3 and IE 6 under WinXP.

Thank you so much, that is very close to what I wanted. I will definitely check to see what you did to make it work.