html, body {
    position: relative;
    width: 1200px;
    height: 450px;
    padding: 0;
    margin: 0 auto;
   
}




.und {
    
    background: url(http://www.southernrescue.co.uk/images/Undercon1200.jpg);
    background-repeat: no-repeat;
    margin: 0 auto; 
	height: 450px;
	width: 1200px;
}