How to make background all over the header section?
===

again.I got one more problem.
I want to divide my page into 3 sections,with 3 different backgrounds: <br>
top_bg , middle_bg , bottom_bg

The problem is,the background has a padding,I want it to show from the start of the page to the end of the 500px background.

Here is my HTML:

    <!DOCTYPE HTML>
    <html lang="en-US">
    <head>
      <meta charset="UTF-8">
      <title></title>
      <link rel="stylesheet" type="text/css" href="style.css">
    </head>
    <body>
      <header>
        <div class="top_part">
          <img src="images/logo.png" alt="logo" />
          <h1>My website name</h1>
        </div>
      </header>
    </body>
    </html>

And here my CSS:

    header {
    	background-image: url(images/top_bg.gif) ;
    	height: 500px;
    }
    
    .top_part img {
      float: left;
      width: 80px;
      height: 80;}
    
    .top_part h1 {
      position: relative;
      top: 18px;
      left: 10px;
    }

Look what I meant,if you didn't understood (my english is not so good):
http://i.imgur.com/qmXiW.jpg

Thanks!