What you might want to Google when it comes to IE6 and lower is to code css specifically for it. You'll need HTML conditional statements:

PHP Syntax (Toggle Plain Text)

<!--[if IE]><style type="text/css">@import "css/IEstyle.css";</style><![endif]-->

<!--[if IE]><style type="text/css">@import "css/IEstyle.css";</style><![endif]-->

That calls all IE browsers, all the code is located in a IEstyle.css external file.

PHP Syntax (Toggle Plain Text)

<!--[if lte IE 6]><style type="text/css">@import "css/IElt.css";</style><![endif]-->

<!--[if lte IE 6]><style type="text/css">@import "css/IElt.css";</style><![endif]-->

That one calls IE6 and lower in again an external file. Of course you can hop right to it and just put the CSS between the statements.

PHP Syntax (Toggle Plain Text)

<!--[if lte IE 6]>
<style type="text/css">
body{
 background: black;
}
</style><![endif]-->

<!--[if lte IE 6]> <style type="text/css"> body{ background: black; } </style><![endif]-->

It might have been nice to show a link to the page, maybe you don't even need to implement conditionals.

Good luck.

add a DOC type declaration.

Also to make the page cross-browser, I would recommend to set to null margin and padding to all elements.

PHP Syntax (Toggle Plain Text)

* {
  margin: 0;
  padding: 0;
}

* { margin: 0; padding: 0; }

The issue is that different browsers set up different margin and padding to HTML elements.