background copre tutto

salve sono nuovo mi presento mi chiamo ivnao ho un grosso problema non so il perche ma metto un background in css succede che mi copra tutto il resto delle immagini e del testo come mai?

Codice HTML:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <title>Layout 7</title> <meta http-equiv="content-type" content="text/html; charset=iso-8859-1"> <meta name="generator" content="HAPedit 3.1"> <style type="text/css"> body { background-image: url(bg1.png); background-color:black; background-repeat: no-repeat; background-position:center top; background-attachment:fixed; position: absolute; z-index: -6; } </head> <body topmargin="80" leftmargin="0" rightmargin="0" valigntop="0"> <table> <tr> <td > </td> <td > <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </td> <td > <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </td> <td > <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </td> <td > <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </td> <td > <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </td> <td > <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </td> <td > <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </td> </tr> </table> <img src="bhome.png" onmouseover='this.src = "bhome1.png";' onmouseout="this.src='bhome.png';"> </body> </html>