Hi I'm pretty new to web design.

I am working on creating a portfolio and the site isn't live yet as I haven't finished it. When I test the page in Chrome or Safari the site looks fine and the way I want. When I try to run it in FireFox or IE, all I see is the background color that my master page has.

Here is the code for the page

Code:
    <%@ Page Title="" Language="C#" MasterPageFile="~/Portfolio.Master" AutoEventWireup="true" CodeBehind="Index.aspx.cs" Inherits="Portfolio.Index" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
    <link href="App_Themes/Corporation/CSS/forms.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/homepage.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/layout.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/navi.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/tables.css" rel="stylesheet" />
    <style type="text/css">
        .auto-style1 {
            width: 162px;
            height: 108px;
        }
    </style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">



<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<meta http-equiv="imagetoolbar" content="no" />
<link rel="stylesheet" href="styles/layout.css" type="text/css" />


<div class="wrapper col1">
  <div id="head">
    <h1 style="color: #FFEE33"><img class="auto-style1" src="App_Themes/Corporation/Images/Logo.gif" /> </h1>
      <p style="color: #FFEE33">&nbsp;</p>
    
    <div id="topnav">
      <ul>
        <li><a class="active" href="Index.aspx">Home</a></li>
        <li><a href="AboutMe.aspx">About Me</a></li>
        <li><a href="full-width.html">Portfolio</a></li>
        <li><a href="Coursework.aspx">Coursework</a>
          
        </li>
        <li class="last"><a href="ContactMe.aspx">Contact Me</a></li>
      </ul>
    </div>
    <div id="search">
      <form action="#" method="post">
        <fieldset>
          <legend>Site Search</legend>
          <input type="submit" name="go" id="go" value="GO" />
          <input type="text" value="Search the site&hellip;"  onfocus="this.value=(this.value=='Search the site&hellip;')? '' : this.value ;" />
        </fieldset>
      </form>
    </div>
      </div>
</div>
<div class="wrapper col2">
  <div id="gallery">
    <div id="Div1">
    <ul>
      <li class="placeholder" style="background-image:url(App_Themes/Corporation/Images/Dylan.gif);">Image Holder</li>
      <li><a class="swap" style="background-image:url(App_Themes/Corporation/Images/casinoThumb.gif);" href="#gallery"><strong>Services</strong><span><img src="App_Themes/Corporation/Images/casino.gif" alt="" /></span></a></li>
      <li><a class="swap" style="background-image:url(App_Themes/Corporation/Images/290x105.gif);" href="#gallery"><strong>Products</strong><span><img src="App_Themes/Corporation/Images/gallery_2.gif" alt="" /></span></a></li>
      <li class="last"><a class="swap" style="background-image:url(App_Themes/Corporation/Images/290x105.gif);" href="#gallery"><strong>Company</strong></a></li>
    </ul>
  </div>
</div>
    </div>
<div class="wrapper col4">
  <div id="container">
    <div id="content">
      <h1>Welcome to My Website!</h1>
      <p>My name is Dylan Creighton and I am a 3rd semester student at Ranken Technical College.</p>
      <p>I am in the Internet and Web based Technologies program and I am hoping that I will be able to find a career that I love doing in this field upon graduation. To the right, you will find a list of content that is inside this website.</p>
        <p>I love what I'm learning, I love what I'm doing and I hope I can be able to do this for a long time. So welcome to my website!</p>
        <p>&nbsp;</p>
        <p>&nbsp;</p>
    </div>
    <div id="column">
      <div id="featured">
        <ul>
          <li>
            <h2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; What's Inside:</h2>
              <p>
                  -A page that allows you to get to know me better</p>
              <p>
                  &nbsp;</p>

                <p>
                    -A page showing works I've done outside of Ranken</p>
              <p>
                    &nbsp;</p>

                <p>
                    -A page demonstrating techniques I have learned while attending Ranken</p>
              <p>
                    &nbsp;</p>

                <p>
                    -A contact page with all my information</p>
              <p>
                    &nbsp;</p>
            
                <p>
                    -A copy of my resumé</p>
            </li>
        </ul>
      </div>
    </div>
    <div class="clear"></div>
  </div>
</div>
<div class="wrapper col5">
  <div id="footer">
    <!-- End Contact Form -->
    <!-- End Company Details -->
    <div id="copyright">
      <p class="fl_left">Copyright &copy; 2011 - All Rights Reserved - <a href="Index.aspx">Dylan's Designs</a></p>
      <p class="fl_right">Website&nbsp; by Dylan Creighton &amp; <a href="http://www.os-templates.com/" title="Free Website Templates">OS Templates</a></p>
      <br class="clear" />
    </div>
    <div class="clear"></div>
  </div>
</div>
</asp:Content>
And here is the code for the Master Page if that's needed

Code:
<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Portfolio.master.cs" Inherits="Portfolio.Portfolio" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    
    <asp:ContentPlaceHolder ID="head" runat="server">
        <link href="App_Themes/Corporation/CSS/forms.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/homepage.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/layout.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/navi.css" rel="stylesheet" />
        <link href="App_Themes/Corporation/CSS/tables.css" rel="stylesheet" />
    </asp:ContentPlaceHolder>
    <title>Dylan's Designs</title>
</head>
<body>
        <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
        
        </asp:ContentPlaceHolder>
</body>
</html>
Appreciate any help someone can give me!