Quale istruzione debbo aggiungere per mettere una immagine di sfondo tipo cotton3.jpg ?

<style type="text/css">
<!--
body { background-color : #ffa040 ; font-size: 12pt; font-family:Arial; color: blue;}
td { background-color : #ffc080 ; font-size: 16px; font-family:Arial; font-weight: regular; color: #570012;}

.select { font: 16px Verdana, Arial, Helvetica, sans-serif; color: #470087; background: #ffa040; }

a { background-color : #ffc080 ; font-size: 16px; font-family:Arial; font-weight: regular; color: blue;}

a:visited { background-color : #ffc080; font-family:Arial; font-weight: regular; color: gray;}

</style>


Grazie
Jack