#resImage_1812 {
    display:block;
    overflow:hidden;
    background-image:url('https://www.urbansquare.net/assets/images/b/products-office-systems-specialist-designer-header-28197c9a.jpg');
    background-repeat:no-repeat;
    background-position:center center;
        width:100%;
    background-size: cover;
        height:600px;
}
@media screen and (min-width:800px){
    #resImage_1812 {
        background-image:url('https://www.urbansquare.net/assets/images/4/products-office-systems-specialist-designer-header-78edec30.jpg');
                height:625px;
    }
}
@media screen and (min-width:1200px){
    #resImage_1812 {
        background-image:url('https://www.urbansquare.net/assets/images/4/products-office-systems-specialist-designer-header-78edec30.jpg');
                height:625px;
    }
}
@media screen and (min-width:1400px){
    #resImage_1812 {
        background-image:url('https://www.urbansquare.net/assets/images/9/products-office-systems-specialist-designer-header-3749f43e.jpg');
                height:625px;
    }
}