#zul {
background : url(../images/zul.jpg) no-repeat;
height : 120px;
}

#zur {
background : url(../images/zur.jpg) no-repeat;
height : 120px;
}

#zcl {
background : url(../images/zcl.jpg) no-repeat;
height : 120px;
}

#zcr {
background : url(../images/zcr.jpg) no-repeat;
height : 120px;
}

#zdl {
background : url(../images/zdl.jpg) no-repeat;
height : 120px;
}

#zdr {
background : url(../images/zdr.jpg) no-repeat;
height : 120px;
}

    <div id="header">
        <div id="zul"></div>
        <div id="zur"></div>
        <div id="zcl"></div>
        <div id="zcr"></div>
        <div id="zdl"></div>
        <div id="zdr"></div>        
    </div><!-- #header-->