#resImage_320 {
    display:block;
    overflow:hidden;
    background-image:url('https://perform.campden.school.firthdesign.co.uk/assets/images/5/seat-plaques-48f30c3d.jpg');
    background-repeat:no-repeat;
    background-position:center center;
        width:100%;
    background-size: cover;
        height:450px;
}
@media screen and (min-width:700px){
    #resImage_320 {
        background-image:url('https://perform.campden.school.firthdesign.co.uk/assets/images/b/seat-plaques-8df12dec.jpg');
                height:400px;
    }
}
@media screen and (min-width:980px){
    #resImage_320 {
        background-image:url('https://perform.campden.school.firthdesign.co.uk/assets/images/7/seat-plaques-feb9b4d9.jpg');
                height:400px;
    }
}
@media screen and (min-width:1400px){
    #resImage_320 {
        background-image:url('https://perform.campden.school.firthdesign.co.uk/assets/images/d/seat-plaques-88726336.jpg');
                height:450px;
    }
}