Their are a few basics you need to get in order.
First, you need to make sure on sizes you use "px". example {top: 100px;} is better that {top: 100;}
Second you can not run-on style attributes, {width: 100px; top: 20px;} not {width: 100px;top: 20px;} As soon as I loaded your page firefox threw a big list of errors at me.
And anything you can put in an inline style you can put in the <style> tags or in a separate CSS file.
Here it is with the problem fixed and cleaned up. Note the width set to the body tag.
HTML Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Test page</title>
<style type="text/css"><!--
body { margin: 0 auto; width: 1024px; }
.divstyle { height: 20px; width: 75px; border: #CCCCCC 1px solid; float:left; }
#divlayer { position: absolute; top: 50px; height: 100px; z-index: 1; padding: 0px; border: #E0E0E0 1px dashed; background-color: #EEEEEE; }
-->
</style>
</head>
<body>
<div id="divlayer">
<div class="divstyle" style="width: 20px;">#</div>
<div class="divstyle" style="width: 200px;">Name</div>
<div class="divstyle" style="width: 250px;">Address</div>
<div class="divstyle" style="width: 300px;">Location</div>
<div class="divstyle">City</div>
<div class="divstyle">State</div>
<div class="divstyle" style="width: 100px;">ZIP</div>
</div>
</body>
</html>
Also as a side note the width you set of 1024 if you trying to make sure the page will fit inside screens with a resolution width of 1024 that will be too large. You aren't counting the border of the window on the left or the scroll bar on the right. I have had to go as low as 990px to make a page fit inside of all browsers on screen with a resolution width of 1024.